That boot time prior to Windows laoding is really strange. You might want to try tinkering with that.
Changing tabs shouldn't be any faster, unless you were starved for RAM (or file caching, in XP's case). Page loading times, without a direct fiber connection, are typically not disk-limited, but network-limited or CPU-limited (ABP/ABE should speed up web access more than any storage tweaks). I've tried the whole RAMdisk browser thing, even, and it's all placebo, with an OS that caches well (like Vista and newer). Turning off disk cache can improve things, sometimes, but OS, RAM, the internet connection, and reducing network activity via extensions like adblock (the fastest IOP is the one not done) are where it's at.
Any time before, when you didn't see the HDD activity light on quite a bit while you were waiting on it, will not improve much by an SSD, but improved by a newer OS (if XP), more RAM (if Vista or newer), and/or faster CPU. Those times where waiting was due to the HDD will be reduced by an order of magnitude, or even a few orders of magnitude. Also, as the OS ages, and files get scattered about, that SSD will keep performance up better than any HDD will (so would several other SSDs, but they were all much more expensive for the size, at the time 🙂).
I'm not sure what you made this new PC out of, but the era of easy high OCs is long gone (with AMD, the settings are fairly easy, but the CPUs run really hot). I built my new system with non-OCable parts, because I knew well that the effort would be much higher than the reward, even if I got a good chip. Plus, the cost is higher, if you don't like near a Microcenter. Sandy Bridge can take high OCs with a good cooler, but is still quite the PITA compared to older CPUs. IB a bit worse, and Haswell a bit worse than that. If it's going to someone else, don't bother, IMO. Just get it running well at stock, figure out a way around the boot time issue, change the driver to Iastor (in AHCI mode, MSACHI and Iastor can be swapped between), just in case, and leave it at that.
Edit: based on searching and finding a prior thread, it seems something was wrong with the setup to begin with, and HS and CPU mating might not be ideal. If it runs stock fine, leave it, and the same for the RAM. There's nothing wrong with 1333 CAS 9 on SB, though it may not be ideal, and a 2500K is only 10-20% slower than a similar-speed Haswell, which is enough performance for any software out there today, and likely that will come in the next few years.