HubStyle is only available in Battle Network 2, It gives you full custom screen, a Barrier at the start of battle, and a ton of other bonuses(I can't remember right now.). However, it cuts your HP in half. Meaning you have to be more careful when using it. It is pretty much a lighter blue Megaman (Similar to how he looks during Full Synchro, minus the ring.)
Well, unless you can flesh out style data in BN3 and beyond, as INC has exposed them in the battle style of BN4. (There's a scenario where you can get the Hub Program, pretty much works the same way)
For me I enjoy (up to 5, I may not have 6):
- Heat Guts (BN2 - 3 Only)
- Heat Armor (BN1 Only)
- Junk Soul (BN4 Only)
- Colonel Soul (BN5 and BN5DS Only)