I've bought many instruments (and amps) online, from GC, MF, and
Sweetwater, as well as many new and used locally. In fact, I had a fantastic bass delivered from SW just last Friday.
I had one instrument with an issue, a plus top Strat that wasn't really new from GC, but my local store made it right on the spot.
MF _is_ GC, but GC adds the option of local returns if you've got a store within driving distance. Sometimes MF has better prices, GC will match them if asked, as they ARE them.
My favorite online retailer is Sweetwater, I've found them to provide top notch customer service. The only downside is returns would need to be shipped, and a boxed bass or amp is not cheap to ship.
It's worth adding that I worked in a local independent music store back in the day and am very experienced and comfortable setting up my own instruments. Setups vary, preferences vary, shipping an instrument can move things, and many are not fully intonated by the factory when shipped. One of my jobs at the store was putting basic setups on instruments shipped to us before they went on the sales floor. Most all new instruments will require some sort of adjustment. If yours does, wait a week or two before you either start or take it to a local pro to let it acclimate back to the world after being in trucks, trains, shipping containers, and/or airplanes.