Around February 2011 I picked up an Apple 27" LED Cinema Display for my home office, as a way to help upsize the screen real estate on my 2008-era MacBook Pro. I loved it, and there was absolutely nothing wrong with it when the Thunderbolt Display came out, so I didn't think anything of it. Then I bought a 13" MacBook Air, and next thing I know, I'm putting the original 27-incher on Craigslist...
But why would I do that? What was wrong with the monitor and why trade it in? Here's my account of what you should do if you're shopping for a new monitor, and have a hankering for some Apple products.
What's the same: If you're staring at two of Apple's 27-inch monitors, there's really no way to tell them apart from the front. There's no fancy Thunderbolt icon, no special trim, each one is a photocopy of the other. They both share the same 2560X1440 resolution, and a lot of the same hardware as well. Ultimately, the only way to find out the difference is to turn it around and look to see how many ports are on the backside. If it's more than three USB ports, you're looking at a Thunderbolt monitor.
What's Different: The biggie here is the obvious, Thunderbolt capability. Where the older 27 has three cables on its laptop connection cable (Magsafe, USB and MiniDisplay Port), the Thunderbolt only has two, discarding the USB for the super speed of the new port. On the backside, that means you've got three USB 2.0 ports, one Firewire 800, gigabit Ethernet, and of course, another Thunderbolt port.
Why Switch? I really debated changing out the monitors. It just seemed silly to spend so much money once, then do it again later in the year for what was essentially an upgrade. But there are a few main reasons that pushed me over the edge.
1. File Transfers. I constantly move files around on my home network between my iMac and my MacBook Air, and doing it over Wi-Fi was painful at best. By adding the Ethernet connection, I increased productivity in the process, and made my laptop more versatile. That was a big bonus.
2. Download speeds. Pulling files down off YouSendIt and other places really was a chore on Wi-Fi, but that's a hazard of my business. Having that Ethernet connection boosted my download speeds substantially, and didn't hurt my uploads either.
3. Building a True Dock. With the three USB ports on my original 27, I did just fine with basic backups to USB drives, but now with Firewire, I can dock my faster drives too. It also means that once more affordable Thunderbolt drives become available, I can really have some high-speed storage at my fingertips, making the small hard drive size on the Air not really an issue.
Should You Make the Switch? Ultimately, it comes down to this: Do you own a Thunderbolt-equipped Mac? If so, then you need to weigh how important the added features are to you, and whether or not it makes the purchase worth it.
For me, the Ethernet cable alone almost made it worth the switch, but if I still had my old MacBook Pro, I would've stuck with the original 27 and never thought of it again. Either way you're still getting an excellent monitor, it's just whether or not Thunderbolt is important to you.
As an added bonus, you can also daisy chain a second monitor to your Thunderbolt model as well, giving you a ton of real estate to work with.
The Ultimate Used Furniture Cleaning Kit
Ana Creates a Community at Home
Good Food to Share 
The Big Book of Small, Cool Spaces 
Apartment Therapy Presents 
The Eight-Step Home Cure 
Z2 iPod Dock and Wi...
Soda Recipe: Homemade Ginger Ale
Recipe: Spring Fruit and Nut Tabouli
Because of a lower grade Thunderbolt chip in the new MacBook Airs, you can actually only connect one Thunderbolt Display. As far as I know, all other Macs can daisy chain displays.
i was just looking up a lot on thunderbolt. My studio decided to buy me a new computer and i had suggested an imac since that is what we have here already, but instead they went with a new mbp and a display. At that point i didn't know there was a separate thunderbolt one and was kind of angry thinking about having to unplug/plug in everything all the time.
Then i see that the thunderbolt display acts like a dock. So awesome. Also awesome that they actually ordered that one since both options are still available. The display is here but the laptop isn't yet. So tempted to try and hook it up to my current imac but there is no need. Just so easy to have the keyboard/mouse, ethernet, and i'll be dasiy chaining a couple fw800 drives all connected and just have to deal with one damn cable.
In the end if you have a new mac and are buying the display, it is a no brainer to get the thunderbolt option. If it was just me doing it though and was thinking about the upgrade, i probably won't take the hit in cost it would be extra after selling the old one.
Also, did a little research and see that you can now transfer audio through thunderbolt though an adapter to hdmi, so you can hook your new macs up to your tv for a little hulu action (i know i will be...)
you know. i was thinking about it more. Although I know this would add cost (but i mean come on it is a $1k monitor...just add this in). I know the front foot is super slim etc, but i would love for them to building in like a 2 port usb dock right there. so you don't have to go behind the computer, always hated this with the imac. Plus you could plug your keyboard and mouse in there. I know your setup is wireless but i can't stand going through all the batteries, even rechargeables... I am on my computer for 8-10 hours a day...
also, come on apple, heard of esata or usb3. i know you love thunderbolt but it would be great if you would play nice with others too.
Huh? What? You lost me at "the older 27 has three cables on its laptop connection cable".
@kushkush For those not in the know, what the author means is that near the end of the cable on the older 27, it splits into three separate cables with the different connections he speaks of. (Realistically, all three cables are inside that one cable, just twisted together until the point where they separate into 3 cables.) The newer 27 only has two of those cables: the mag-safe power and the thunderbolt cables. Since the cable actually splits into 3 (or 2 as it were) cables, this is not a single cable with multiple connectors (interchangeable or otherwise), although some might think that not understanding the design.
nice article, debating making the same switch, worried about fan noise from the macbook air using the thunderbolt. any comments on this?
Dear Kevin, and reader:
I know this comes late after your publication but anyway...
It seems your main reason to spend about $1000 dollars on a new display was the Ethernet port. I hope your net expense after selling the LCD was under $29 because that's how much an Apple USB Ethernet Adaptor costs. http://store.apple.com/us/product/MC704ZM/A/apple-usb-ethernet-adaptor
Thanks for the article.