Replace with your choice. I prefer the extra safety of 2 stage in a semi. And it doesn't take much getting used to, in fact if you can't get used to it, it would amaze me. 2nd stage at 1.5 pounds on some are pretty sweet and pretty light for a semi.
Tuning anything stock other than just a tiny bit is the dumbest thing one can do. I say that with mileage under the belt. It takes way to much work and in the end it will usually double eventually if not more. OR what you accomplished was so little it didn't matter really. I say this having won some matches with a 7 pound plus trigger once that failed and I had to get it to pass weight and no time to tweak...
RRA or La Rue are cheap enough. Usually pretty decent. If not they can use a bit of tuning to get good.
When its important I'd go Geiselle these days but others YMMV.
