I had a long discussion with our transition trainer about these departure options last night. Tom is a man with thousands of hours in RVs, makes his living entirely within the RV world, and is regarded as a leader in the homebuilt world.
His preferred departure procedure (and it's the one he taught us) is quite simple, and has no connection to V speeds at all: Put the glareshield on the horizon.
This allows for maximum forward visibility, with better than Vy cooling. In his opinion (and I concur) THIS is truly the "safest" departure method.
WRT a Vx departure, he agrees that the -8's extreme deck angle at relatively low airspeed compromises cooling, reduces forward visibility to zero, and is only needed on that rare occasion when you're on an extremely short strip with big obstacles at the end of the runway. If the big fan quits during this type of departure, the pushover to prevent a stall will be extreme.
WRT zoom climbs, he just chuckled and said "They're a lot of fun."