Then you'd probably do well on a more "conventional" Waterbury routine, like 10x3. GVT can be pretty rough, I've heard. And 3x5 is too low volume to produce decent hypertrophy gains. Any reason you narrowed the field down to these 2 routines?
That's probably why Waterbury didn't design the GVT program. Some people only drink black coffee. Some people only drink coffee with half-and-half. And some people only drink decaf. Everyone has their opinions, but that doesn't mean anybody's wrong.
Again, everyone's got their own ideas. Waterbury likes anywhere from 2-4 times per weekt, per part. Other coaches prefer more minimalistic approaches.
Try one routine for a bit, if it doesn't "feel" right, try something else.