Tim Dowdle

I'm looking for pros and cons for SVI frames/guns vs STI frames/guns. I've shot IDPA for 15 years to avoid the high cost of an open gun. I want to buy or have an open gun built. I see more STI guns on the range, but I've looked at the SVI guns and they are impressive. I'd like to hear from some experienced open shooters. While we are at it, what cartridge is king for comp guns these days? I didn't think 38 super would ever be beat, but I see a lot of 40's at matches.