Thing about tightness is that is is all relative.
Generally BKPs are tighter than the usual suspect brands. My crawler, by rather a lot the loosest of the BKP bunch, is still at least medium tight when compared to some of the other stuff out there.
The Crawlers voicing combined with my gear (Orange amp) will never get a truely great tighet modern metal sound, suprise suprise, but still.
All in all alnico BKPs are tigher than most of the other ceramics...now donīt get me started on BKP ceramics.
It is just that general clarity of BKPs, which is just so bloody amazing once you realize what you are playing now...whole nother world opens up.
For tightness you got the Amp, the cab, the PUs and the pedal chain (and of course the string gauge, etc.), which all make a huge impact. A booster or OD goes suuuuch a long way when it comes to tightnes (god I love my Super Hard On clone).
What I am trying to say is: Both the A-bomb and the C-bomb will be tight enough for most people, especially those who are used to those other PUs. It may take an OD (which is rarely a bad thing for distorted sounds on a valve amp) or a different EQ, but that is basecally standart when switching between guitars or PUs anyway.
So a C-bomb should deffinetly get you what you need: Growl and enough tighness.