Yea I definitely felt the ability to hit with a looser grip with the smaller grip and felt the wrist lag come into play. It was atrociously humid when I was playing though so I was worried about letting the racquet out of my hands. I think it just doesn't work with my body since I have weak wrists from snowboarding and spraining them.
I don't care for smaller grips myself - just my personal normal after growing up playing serve and volley tennis and doing lots of business up around the net. A larger grip gives me much more confidence up front where I want to have a lot of control of the racquet face. Volleying well usually includes employing a firm degree of grip pressure, but a small grip (4 3/8" or less) will usually trick me into squeezing too hard when attacking the ball and looking to volley with authority.
I can get away with a smaller grip size around the baseline, but I can't grip the handle with lighter pressure back there if I don't have much of a flare at the bottom of the handle - at the butt cap. Even a larger grip size will feel like it can get away from me if I swing too hard without that bump to keep the handle from wanting to slide through my fingers. That will also trick me into gripping too hard.
You don't need to build up the flare at the bottom of your handle too much - Richard Gasquet has what looks like a small door knob on the end of his racquets. But if there's a comfortable amount of flare there, I find that any racquet will swing fast for me using rather light grip pressure. That means lighter grip pressure for strokes, but also for serves and overheads. I think this is a big deal because the serve seems to really demand lighter grip pressure if we want to get the racquet going rather fast over the top. Too much tension will kill the loose, fluid arm and wrist that we need through contact to hit those shots well.
When I put a replacement grip on my own racquet, I might put a second layer over the butt cap before I start spiraling up the handle to get that extra bump that I want to feel down there. I might also use an old overgrip to create a little extra buildup there - just a layer or two, tape it into place, and then apply a full overgrip over the whole grip.