I'd say it totally depends on the bird's personality...
as you can see, there are big differences between what everyone experiences with their pis. While having some similar traits, they're completely different.
Every one agrees that your baby bird's character will evolve when it matures, but the extent of these changes is unpredictable and depends on many things...
All I can say for sure is that you don't generally see as much agressive behaviors with pionus parrots than with many other species. It can still happen though! and possibly more with males than females, apparently. I guess you'll just have to see how it goes with your pi.
Lovebirds are known to be agressive and teritorial... but it doesn't meen they're all hormonal monsters.
The trait I love the most with my BWs is their ability to bond to many birds and people. It makes them great family pets and limits bonding issues! (that greatly complicate things when hormones kick in...)
I often hear that BWs are on the quiet and reserved side compared to maxis and blue heads, whereas white caps and duskys are supposedly more "high energy" and temperamental... but I have no idea if it's true... again, I think every pi and it's bird/human relationship is unique so I would just go for the pi you feel the most drawn to. In my case, it was BH and BW and I only knew of a good BW breeder so my choice was easy to make. I hope to add a blue headed girl or two to my flock in a few years... when my big aviary is finished... let my guys choose a mate if they feel like it... (no nests and babys though!) I just love to see them in flocks.