What kind of death metal are we talking about?
It's a pretty diverse genre.
A lot of the '90s style stuff like Nile and Cryptopsy is very EMG sounding, and favours dry pickups.
My local guitar shop is owned by a death metal guitarist who tunes down to A, and I asked him the other day about his sound, which is based on EMGs 81/85, and he said that it was important that the rig had a lot of mids so that it sounded tight and his guitar did not end up sounding like a bass in that tuning, hence the V30s, TS-9, etc etc. I think a dry pickup is also a part of the effort to go to low tunings without a muddy sound.
If you want to hear what tuning to B with normal '80s string gauges and bassy rigs sounds like listen to Bolt Thrower's Realm of Chaos. After that album they switched to C# standard. A few bands used to play with floppy strings like that back in the day though. The B-side of Napalm Death's first album is the same tuning, only they play faster. The first Carcass album, notorious for its bad production, has the same issue of low tuning on regular '80s strings and gear.
A lot of the '80s death metal bands used Dimarzios or something like that. They had a 'juicier' sound than the '90s guys, and tuned to C (Autopsy) or higher. Asphyx was in D standard or even drop D I think
I am happy with my A-pig for death metal stuff but I don't go for the super-tight sound, not sure how it stacks up playing that stuff. A C-pig might be a better choice for some of it. On the other hand if one balances really low tuning with a brighter setup maybe something like a Rebel Yell would work.