Coach French fry
,
Just play "open" for now, when you start an official League then you could choose a certain weight standard 3.3 , 4.0 what ever.
To answer your qestions on the difference the weight makes in performance of a base. If two bases are tweaked "equal" in strength than the heavier base/figure combo will be stronger.
For speed I have found that the biggest difference is it "settles the base down to be "smoother"
These are just my opinions and what I have found to be the
basic differences.
Geno H