I like G4 snakeman not because of its design but because of its sheer unpredictability...
Boundman was still personally my favorite out of the g4 forms, packed legitimate top tier power(King Kong gun)
time limit however makes it the most annoying form in existence
its powerful but the gap between it and g2nd/3rd also made its drawback so annoying.
with g5 only issue is the cartoon stuff might not fit the tone of every fight.
realistically we should not see any of those forms anymore anyway.
cause in g5
luffy can be as fast as he is in g2nd
he can inflate his bones and muscles however he wants like in g3rd/4th
in addition to controlling his environment
all without the harsh drawbacks g4 had. If I see luffy in any other form henceforth , I know oda is a troll.