I think what is preferred depends on one's personal preference.
Their are many still loving the GSD for it, others that
go with Dutch or Belgian Shepherd, Rottie, Corso or Dobie. However
American Bulldog and APBT are both a good choice. (I've had and like
both these breeds, so maybe I'm a little biased though I've also had
some mentioned above.) There are also a host of other breeds too.
APBT's have done well in SCH, OB, agility, dock diving, weight pull, ect.
They are usually apt to please and have plenty of strive. A lot of them
could excell in many fields if they were given the chance. They love to
be mentally and physically challenged IMO. They are also quick learning
and obey very well. There is always going to be variance in
temperament, drive and energy level, biddability too. I've found that
some of the very high energy dogs are not as quick to learn or maybe
listen, they are more impulsive too, some anyway. It takes more
repetitions for them to get something down but they are willing to
learn and work. Though the combination of training-obedience/play-work is
good for them mentally. The ones which are more mellow but still drivey
tend to listen and learn quick at times and when its needed put their
all in full throttle, putting just as much into it as a hyper dog that
has lots of energy all the time.
If you want to avoid those type stay I'd away from American
Bullies. There are some exceptionally nice AmBullies, they are a larger
boned dog but balanced, not kept fat but lean and muscular and they
actually work. But those owners/breeders are few and far between. Most
are overweight dogs bred for the "hormone since birth" look as you
describe it, no proportion and sadly some are actually deformed and
people think it looks "cool".
I'd recommend going to a breeder that does
these things with their dogs or one who is breeding dogs with the
temperament you desire, along with a good structure and drives. Many
people who do actually do these things with their Pits did not go to a
breeder that actually did SCH or OB with their dogs. They sought a
driven dog and put the training in.
Of the top 20 UKC super dogs currently 8 are APBTs, 4 of the top 5 are APBTs with a tie for first with a Beauceron (another breed I admire). 3 of the top 20 are SBT too. In top 21-40 10 are APBT and 4 are SBT. Many love to be doing something, working with their owner. So I think it is quite possible for you to use an APBT if that is what you desire. They are most certainly a versatile breed.
What I would like to do is for our club to have some sport events that the dogs can really enjoy. A lot of people do the tradition weight pull which is fine, but there is so much more that some of these dogs really like to do. I'd like to add at least sled sprint, hang time, high jump, treadmill race and lure coursing. One dog from my litter is a CH which is just about looks, they took her to be evaluated for possible sport training, which she did very well, when they said they wanted to train for that I said go for it. At one point they had looked into lure coursing, you can do it for fun but NOT for competition without a sighthound. Seems very unfair to me. I know it is something made specific to that breed type but if anything they could separate sighthound and non sighthound competition.