I've owned J-Custom 7s with peizo and 2027s with peizo and even some 6 string with it.
Personally I think the EBMM JPM7 is the best 7 string ever, and for that matter the best dang guitar I've ever played feel wise and sounds superb! The ebmm peizo has adjustable bass, mid and treble controls. However the peizo on the
Ibanez guitars is amazing and I honestly don't think one is better than the other, even though ebmm comes with extra settings. I think the peizo in the ibanez is setup with optimum sound. If I had to choose one over the other, I think the ibanez peizo would get my vote, but only cause I remember how sweet the S2020X sounds! I don't think the 2027s sounded quite as good as the S.
That said, I love the S2020X wow what a sweet guitar, wish I had another. Of all my 7s(10 or so) I've kept only one... EBMM JPM7 blue burst with peizo! I feel like this guitar was perfectly custom made for me, well except I'd use different inlays if it actually was but other than that, its perfect! I wouldn't change a thing outside of the inlays, which I like the sheild inlays, but not with his initials :-( so I just got the dots instead.
You guys are going to be perfectly happy with the peizo on the the guitars, however the sound the best when not driven through an amp designed for metal

or atleast have some compression and a nice acoustic setting on your rack(if using one). I'd also recommend a
BBE Sonic Maximizer for peizo, or any clean tone for that matter.