Just installed two SSD in my enormous PC. And things gone fast: I have Win7 loaded in 10 seconds with all programs from autorun, internet connection switched online and stuff.  Why the hell we used clumsy slow and buggy OS that loads for over half-minute – this is a biggest question right know. Microsoft doesn't deserve money for their damn Windows.
(Well, i need to be honest loading BEFORE OS – BIOS and other low-level shit – also takes about 5-10 seconds, but anyway – ten seconds to fully load the OS – Wow! And, yes, it's better than loading from HDD)
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Some advices for a person who want to upgrade his/her PC with SSD:

• Do not take Crucial M4 or Intel 520 (5xx series is okay but 320 is obsolete for sure) - there's new generation of SSD today that more relible and provide higher performance than that two popular SSD models.


• Also do not take SSD on SandForce-2281 controller – it has poor speed with non-compressible data and not so good TRIM. Also they're significally loose in speed after some time you use them (and when free space is low).


• I can recomend SSD on Indilinx Everest 2 – all reviewers got good test results in speed and reliability. (Also I have one


• Also good SSD on Marvell 88SS9174 controller and Toggle Mode DDR: Corsair Performance Pro and Plextor M3S (or, better, M3 Pro) - very decent drives in all parameters.


• Though i should say that Corsair has high rejection rate in their production of q3-q4 2012, beware.


• The more free space SSD have, the more speed you get


• Larger SSD are faster than lower capacity SSD. For example 256Gb SSD have higher speed rates than 128Gb, 60Gb and lower.


• SSD have short life cycle. Just be prepared for the mopment that you computer will work slow or getting strange errors from knowere – backup your data and keep track SSD health.


• Electricity jumps can kill SSD. If you have troubles with electricity at your place, note that. Also do not cut power and buy a quality power supply for you computer


• If you plan to upgrade your laptop to SSD, check BIOS and manufacturer site – sometimes there's no avaliable options to tweak and your laptop just wouldn't see SSD or fail to load.


• If you have motherboard with Intel Rapid Storage Technology support (Intel Z68 chipsets and above, check your motherboard manual), you can boost you HDD performance using SSD. This is safier than migrating to SSD with OS and stuff, but a bit trickier.

You must set your SATA mode from AHCI to RAID. Normally you should to reinstall windows to work in RAID mode, but there's the way without reinstall:

1. Press Win+R and type regedit. Then Enter.


2. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\iaStorV.


3. In key "Start" change value "3" to "0".


4. Go in branch HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\servic es\iaStor.


5. In key "Start" change value "3" to "0".


6. Close regedit.


7. Reboot computer.


8. Enter in BIOS.


9. Change SATA mode from AHCI to RAID.


10. Save changes and exit from BIOS.


11. Reboot computer.


12. Windows will reinstall all drives and ask you to reboot.


13. REBOOT.


14. After this you will have your system in RAID mode withou reinstalling the OS.

After that you must install Intel RST driver and, yes, reboot again When OS booted up you'll see IRST icon in system tray, double click it and go to the tab where you can boost you PC up.
IRST have effect on boot time, programs' launch speed (yes, games affected too, if you have enough space on SSD, 256 Gb is nice, lower – maybe not).
Wow, that was long, but i hope it's helpful. \
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[UPD 22/12/2012] There's new cool SSD with new out-of-shadow-controller LAMD LM87800 – Corsair Neutron GTX – all hail the new king! Extra fast in most operations, nice blocks recovery after TRIM, however isn't that cheap... (Well at least 240 Gb version).
Also seems OCZ Vertex 4 not so perfect – it has some strange behavior when you use half and a bit more of it's free space, then read/write speeds falls down wildly, and after about 15-25 minutes they're fail to restore to former values and remain slightly lower than before. Also Vertex 4 slows down when command (read/write) queue is long. Anyway it's faster than HDDs
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TL;DR: SSD are cool, buy them. All. Now.
Or not. You decide, y'know. Just sayin'. Yeah.