What kind of SSD in 2011 iMac - Noticeably fast?

Question

Hello,
I currently have a 2010 iMac (the 21,5" entry model), and I'm considering either replacing its HDD with a Solid-State Drive or buying the 2011 version with a SSD from factory.
From what I hear replacing the HDD on my iMac will void its warranty; and even if not, I will have difficulty selling it due to warranty questions. Also, the 120 GB of the SSD I'm considering may not be enough.
My friends who replaced their iMac's HDD with a SSD (Sandforce controller, 120 GB) say it changed the performance dramatically - boot times down to about 22 seconds, programs launching almost instantanously, faster responses overall, even shorter shutdown times.
Is this also the case for the "factory option" SSD for the 2011 iMac? What brand/model SSD does it use, or at least, what controller does it have? In short, do you think adding the factory SSD option (600 $ in the USA Store) is worthwhile, or are users better off installing a SSD (the latest/most advanced ones) they bought themselves? And do you think TRIM support in Lion will work with any of them?
According to your responses, I will consider saving up for a 2011 iMac with an SSD (though, truth be told, I'm afraid the price in Turkey will be out of my budget) or talk to local Apple service shops about replacing my current iMac's 500 GB HDD with a 120 GB Sandforce SSD I will buy myself.
Thanks in advance,
- Onur

Answer 1

Irfon Kim-Ahmad,
I did some Googling, and it seems the 2011 iMac's have a Toshiba SSD. They're slower than a recent SSD you can install yourself, but you can run into warranty issues and installation of a drive into an iMac is difficult. Also, the SSD you can get BTO from the Apple Store supports TRIM out-of-the-box with the Snow Leopard that comes with the iMac - other SSD's can maybe support it with tweaks but I'm not sure.
I was considering adding a SSD myself but I think getting the SSD from Apple is the safer option. If I install an SSD later I may get (as an example) 500 MB/s sequential transfer speeds instead of 250-300, but in everyday use it's not easy to tell the difference - definitely not twice as fast, unless while copying a very large file to another such SSD. The "random read - I/O" is more important for an SSD anyway and both SSD's are more than good enough.
I wish Apple offered a 128 GB SSD option, though - I don't really need a 256 GB boot drive, and it would be less than half the price.
Thank you for the message. And sorry about the late reply - didn't have enough free time and then had to travel abroad for a week, so I can only answer now.
Edited: Found out the hard way that
1) You "can" label your own messages as helpful (probably "solved" too, won't try that)
2) You "can't" take the label back. So, it will stay as an embarassing reminder.
Note: I definitely wasn't trying to "give myself points", I was just wondering if it was possible.