In response to the previous post, the gx4's finish is far more like what is on my shield than what I have on my other rust happy taurus pistol. I haven't seen a bit of corrosion on it yet.
I've had my gx4 out several times. The trigger wall hits fast and was stiffer than what I am used to. Very first shot I had to back off, take a breath and start again, using more force this time. IMHO that's not a bad thing for a carry piece. Reset is short and tactile. Interestingly enough I shot much tighter groups with this pistol than my shield 1.0 or other pistols I have. I got in trouble at the range for "rapid firing" although I put all the shots into a nice tight group.
I replaced the front sight with an ameriglo from the taurus store (~30usd). I'm not sure if the upgrade was worth it (for me), not without replacing the rear sight as well.
I only had stock 11rd magazines. The floor piece has lots of pointy bits which really bit into me when in a traditional mag carrier. I ordered a couple of 13rd mags which are nice and rounded, problem fixed. Because the TORO version has and 11rd and 13rd instead of 2 11rds I might suggest purchasing it instead just for that, as the TORO version is about the cost of another magazine more.
I see the gx4 approaching the 250usd mark with the TORO version nearing 280usd or so. For the quality of this pistol, the full length slide rails (instead of typical tiny ears), and ease of full disassembly, and the noticeable improvement of build quality, fit and finish over the g3's I'd have to say that this may be the best pistol value on the market.