i have one and it's fantastic. I like the 220 as opposed to the 226 because the single stack mag makes the grip thinner and IMO nicer. That being said, it's not a good gun for ipsc because the mags only hold 9 rounds.
Someone can correct me if i'm wrong but i think to turn it into a .45 you need a new slide, barrel and mags and as mentioned before, these were originally barreled in .38 super. I'd love to get a .38 supre barrel for mine, but have yet to see one for sale anywhere.
All in all it's a good deal for the money. I actually got mine slightly used from these boards for about 650, which IMO is a GREAT deal for a genuine Sig.