I agree with both of the above

I use a mix of P3, Citadel and Vallejo paints. Citadel's washes and foundation paints are a thing of beauty and I still like their metallics. P3 are also very nice and different tones than Citadel, so if you're looking to replace your Citadel paints with P3 your minis will look different. And I absolutely LOVE P3's Armor and Flesh washes. They're a bit different to get used to but once you get them down they shade flesh and metal bits perfectly.
All in all, use a mix of paints that fit your style, just be aware that the lines are different and if you completely switch lines the colors will be different. Mix and match is key,
IMHO.