Yes, no drawback.
When Luffy first learned G3, his time was so limited he would turn into a child once the time is up. When Luffy first learned G4, his time was so limited he would turn into a sitting duck once the time is up
Now there is no drawback in G5, the exchange for that is: Contrary to gap between gearless to gear 2, gear 2 to gear 3, and gear 3 to gear 4, the gap between Gear 4 and Gear 5 is just very small.