I have a DH bike with 29" wheels and I like the stability when I'm airborne. I bet you'd get used to jumping your bike given some time, if this isn't just about looking for a way to justify buying a new bike. If you are just looking for an excuse to buy a new bike then hell yeah, get a 27.5"!
Check out this dude named Max with the M29 (which literally used to belong to Aaron Gwin). He's on a 29er designed for World Cup DH racing and can throw that thing around like mad, so it's not the wheel size that decides if the bike is nimble and jumpy:
Check out this dude named Max with the M29 (which literally used to belong to Aaron Gwin). He's on a 29er designed for World Cup DH racing and can throw that thing around like mad, so it's not the wheel size that decides if the bike is nimble and jumpy: