Small world!! I'm from Lexington, although I haven't lived there since I got married in 95 (and only for summers 91-95) so I'm not up on a lot of stuff.
Lexington is a nice area, although you will find it to be a little less cosmopolitan than Charlotte. Homes are pretty affordable....and you can find anything from neighborhood homes under $100K that's nice to $1million estates on Lake Murray....and everything in between.
Lexington has some of the best schools in the Midlands area...although I can't remember if it's Lexington 1 or 5 that is the really good district.... It's close enough to Columbia that working there is an option, too, but the only really good district there is Richland 1 (or is it 2....see....been awhile!). LOTS of people live in Lexington (city or county) and commute to Columbia for work....so traffic can be a bit bad in rush hour times.... There are nice areas in both Lexington and Columbia, though, so I'd prefer to live where I was working....(I hate commuting).
The Irmo area can be a zoo, but that's where the good mall (Columbiana Mall) and related strip malls are....also some good neighborhoods....but I'd definitely check out the traffic situation before settling on an area.
Feel free to PM me if you have any specific questions.....