A set of L keys are useful, but modern vehicles have fasteners that need some sort of hex bit - you need both the reach of an extension and the leverage of a long handle for a lot of fasteners.
As for hex bit sockets or bits and adaptor, it depends on a couple of factors.
Firstly budget. Decent hex bit sockets can be expensive, and buying cheap ones is a false economy as they are prone to twisting. (If you must buy cheap, get cheap normal sockets and decent hex). Perhaps better to buy an adaptor and some decent bits.
Also consider size. If you want to remove screws with a 10mm hex (or a big torx - same applies) you really need a proper hex socket and a 3/8 drive handle! If you’re doing small stuff, the 1/4 inch adaptor works fine.
I have a right mixture - in 1/4 drive I have an adaptor and some good quality bits - mostly PB Swiss and Snap On. The few hex bit sockets I have are for specific applications. I can get a very comprehensive set of bits (slotted, Pozi, Phillips, Torx, inch and metric hex) in a very small package, and they fit my bit drivers as well!
In 3/8 drive I use entirely bit sockets. A few Snap On, but mostly KoKen (the cheapest that don’t twist, I’ve found) or Hazet (about the toughest)! The only bit adaptor I have is for 5/16 bits. No risk leaving a bit in some inaccessible area this way, which always seems to happen sooner or later with magnetic bit holders!
In 1/2 drive I usually only buy as required, but that’s given me a comprehensive set of Inch size bits, mostly used on machines. I do have a very nice Beta bit adaptor that uses their own 10mm bits. I have a full set of hex and torx in these and they seem to be good. Don’t know why I don’t see more of these about!
