I am a big fan of the SIG 229 (actually the 228) in 9mm, but much less when chambered in .40. The slide just wasn't as smooth when cycled. I carried a .40 229 for about 6 months before turning it back in for a 9mm one.
I have much fewer rounds through the P30, but the fit and feel of the controls seemed to fit my hands better. Operation of the action was very smooth and comfortable. But, as expected, the trigger felt horrible...I don't think H&K has put out a good stock trigger since the P7.
IF I had to choose between the two above, I'd go with the P30 and send it off for trigger work
In alloy, I prefer the Beretta 96; in polymer, I prefer the M&P40