I just feel things like furious actions, evasion and short hops, all out attacks, one more bursts, gold bursts giving full meter, the crazy shit you can do from fatals just generally make the game feel more evolved and refined, which is to be expected given each games age.
You don't sound like your having a go at all.
I think if you could sit someone down having never played GG, BB and P4U and asked what there favourite is based purely on mechanics (forget preferences on characters, music, graphics etc) I don't think many would choose guilty gear, just cause it doesn't have much BB and P4U don't.
I'm not saying for one second your wrong to prefer guilty gear but I do wonder how much of your preference is skewed by nostalgia. I often wonder myself how much my enjoyment of old games are nostalgia as opposed to the game being great