I used to think my matt black VIP was ugly but after seeing the GP-6 I've uprated the VIP to merely "plain".
I've never had a PX-4 apart so the descriptions I've found on how the GP-6 differs from one are lost on me.
I don't have any knowledge on the trade-offs associated with tilt vs rotating barrel but I'd speculate that the legion of folks making 1911s and the additional legions tuning them might cloud any "versus" analysis. There's not a lot of places one could send their spin-barrel for a Camp Perry tune-up.
To offer a sorry analogy, tilt-barrel vs rotating reminds me a bit of "small block Chevy" vs. "Wankel rotary". The latter might have some advantages but it had better show up at the party already doing everything you need it to do - you won't find a speed shop specializing in them on every street corner.
I wonder if rotary barrel thing-a-ma-jigs couldn't compete heads-up if they had similar resources behind them. Gross speculation on my part, but that's the beauty of the intertubz - no penalties for uninformed speculation.