Thanks for your views on this, DM. Much appreciated.
I've in the meantime been seeking further insight into this aspect of using SSDs on a forum dedicated to the ins-and-outs of the imaging software called Ghost. I use an early version of Ghost at present. It's simple and it works.
I'm not sure if I've got this the right way around but the thing I've gathered about SSDs is that they differ from conventional HDDs in that SSDs require 2048 sector alignment, whereas conventional HDDs use cylinder alignment. Apparently, WinXP assumes cylinder alignment, as do legacy imaging utilities, and if you try to mix the two, as it were, you end up with a very poorly-performing SSD (speedwise).
Judging by some responses from that forum, though, there are one or two partitioning pieces of software around now which can deal with this problem. One of them is available online free. It's called GParted, and appears to be some sort of open-source software. I've yet to fathom, though, whether using that I'd still be able to use my Ghost imaging utility and could continue using my external conventional drives on which I keep my partition images. I rather doubt it.
The brand of SSD I've had in mind has been Crucial. Prices of their SSDs are certainly coming down gradually, even in their m4 series. On their website there are some useful guides in the form of videos and one of them explains that you can purchase a 'transfer kit' from them to initially copy partitions from your existing conventional HDD to the SSD(s). This kit comprises both software on a CD and a special hardware module that you temporarily plug into a USB port. But the video doesn't say whether this solves any alignment problem. I think I'll need to probe Crucial for some detailed answers on this.
More generally, there seems to be no compatibility issue in using any of Crucial's latest SSDs with a Gigabyte P55-US3L motherboard. Although optimised for SATA3 connectivity, these m4 SSDs will work fine on any of the US3L's SATA2 ports.
I concur with your cautious viewpoint, DM, but it seems to me that SSDs are the way forward in drive technology and that ultimately that's where we'll all end up. SSDs have some very desirable features, let's face it. In making the transition, I'm pretty sure that 90% of us won't want to install our operating system and all our apps from scratch, so the use of some sort of imaging software will need to come into it somewhere. But for me the big question-mark over SSDs at present is this issue of data alignment and of trying to make a conventional drive work together with an SSD, if only on a very temporary basis. There's also a niggling doubt as to whether any modified motherboard drivers would be required. In your dealings with SSDs, DM, did you find the need for any new drivers?
Postscript: I've been back to the Ghost forum. The guru there on this matter has reassured me that I will be able to continue using both the Ghost utility and the external conventional drive. From what he says, the alignment problem essentially affects only the SSD(s). Once the SSD(s) has been realigned, there should be then no issues. He's even explained the procedure for using GParted to do this for my particular scenario. It involves putting a particular version of GParted on to a bootable CD. Once the SSD has been re-aligned, you can apparently do everything you did before with your drives with gay abandon! He reckons that the Crucial kit is only necessary if you want to initially create the new unpopulated partitions in the one transfer operation. His method instead creates the partitions separately and speeds up the entire process.