There really isn't anything all that wrong with the factory base other then the slots limit your mounting options.
My issue with most of the aftermarket 10/22 bases is that most of them are just too tall IMO. I guess that's fine if you are mounting a large scope and need the clearance but I tend to go for smaller scopes on the 10/22 (40mm Obj tops but usually stay with 36mm or smaller) and like to mount them as close to the bore axis as I can, especially with stocks like the factory one that do not have a raised comb. This also an area where I don't see any reason to spend big money.
If you don't have a need for an extended base, I've found the Weaver Multi-Slot Base (430T) is actually a decent base for not much money.
If you do need or want an extended and are willing to spend a little more, I recently picked up a DLASK Arms base (
DSLAK at Brownells). I got the .375" model but I like that the offer different height bases so if you need or want a taller base for whatever reason, you have that option.