Unfortunately, Apex has buried the venerable Allen brand.
I’ve always been fond of Bondhus hex wrenches, though sad that they discontinued the short ball-end sets before I picked up a set of metric ones. I carry a set of the short Imperials pretty much everywhere:
(The metric set in the above photo has been replaced w/ a Bondhus holder and a Wiha subset from a larger Wiha set in my frequently used tool roll)
Another well-respected U.S. brand is Elklind (my two main sets, sold under the Popular Mechanics brand are from them) which last I checked made the hex keys for Snap-On. If you want discrete bits for a 1/4" driver, the Bondhus ones are quite nice, and Chapman Manufacturing does great sets.
Wiha are quite good, and Wera is well-respected (though some claim quality on the latter has dropped off since production was moved to eastern Europe).
Thorp is well-regarded in the RC vehicle community, and most of the upper-echelon bike tool brands (Park, et. al) are good, and I’ve always had good luck with the better Japanese brands such as Beta (see the Niwa tools in the above photo).
PB Swiss are among the best brands easily available, and I’m very impressed by the bits in my Victorinox bike toolkit.
While I love the insert bits (esp. paired with my nifty Silca T-Ratchet + Ti-Torque Kit), there is definitely a place for the L and T style dedicated drivers — most notably on fasteners which are located so as to not admit a bit driver holder (my wife’s fencing foils come to mind).
On my wife’s fencing foils the fastener is at the top of the handle and reached from the bottom through a hollow which barely admits the fastener or tool.
I have a reasonably inexpensive set of Husky T handles. Also have a set Bondhus regular and long L’s with ball ends which are decent for the price. For larger stuff like motorcycle maintenance I use Craftsman 3/8” drive sockets. I have plenty of odds and ends too. I have a couple good Snap-On ratcheting screwdrivers that will accept inserts, but rarely use them for that (they’re really good screw drivers, but lack the clearance as Will mentioned to get into tight spaces). Funny enough I bought a full set of metric and Imperial from Harbor Freight several months ago and they seem hard and work great(unlike a lot of the stuff I’ve bought there). As a past aircraft mechanic I’ve got a fairly large collection of tools without even talking about wood working tools. I usually try to “shop for the best I can afford”, but that doesn’t always mean inexpensive is no good. I’d recommend at the very least a decent set of T-handles and a set of the Bondhus L’s in both metric and Imperial. If you’re like me at all you’ll have 10 sets of various stuff over time, haha!!!
I will disagree with the view that the 1/4" hex inserts are worth much.
A set of ball-tip L wrenches and a set of Tee handle, each in both metric and imperial, are MUCH more useful. I have older Allen, Craftsman, and several others (I leave the appropriate wrenches at each machine as well as a set of L wrenches in each travel tool kit), and lately have been going to the Bondhaus. I also have some Husky, because I needed a particular size and the ornge place was the only place close by.
I rarely use the 1/4" drive hex, since, so often, the screws are in places where there is not enough clearance. I do use the 1/4" hex for many other types of screw (star drive/torx, posidrive, phillips, etc) as they are usually found as surface flush fasteners or, at worst, with plenty of clearance.
I’ve used insert bits for everything on the Shapeoko, I don’t know what you guys are attempting to access that you cannot hit with an insert bit + handles.
The only thing I can think of is maybe on the standard size unit, the screws for the waste board that fall under the left/right extrusions. I have a low-profile spinner handle that works, but I just dedicated a bit and a disc of wood to a purpose-made unit that is 100x faster than any L wrench.
I’d start with a $15 set of insert bits and see what I need beyond that.
I have a set of Long Wera Metric “Allen” wrenches. They have square ends on the short end and ball tips on the long end. They are very hard and do not round off. I bought a set of T-handled metric from Harbor Freight and do not recommend them. The HF set is soft and I keep having to grind them off. I need to throw them in the trash before they get me into trouble. Be extra careful when using an Allen wrench. Make sure they are fully inserted before torquing them. A rounded out allen set screw is hard to remove. Buy a good quality set and not cheap sets. The quality of the steel is important and the difference in price between a good set and a cheap set is not significant when amortized over several years of use. I have some sets for using in a 1/4 inch screwdriver type handle and they work good for larger sizes. For small sizes use a good quality hex key with the flat end inserted. The ball type are ok but smaller sizes are very easy to strip. If you use thread sealant only use “Removeable”. If you use permanent that means you will never want to remove the screw. If you do use permanent thread sealant you have to heat it up with a torch to liquify the sealant. A torch can be very detrimental to things around the set screw.
Also remember to tighten with the short end of an L shaped allen wrench. The reason is about the torque you can apply. The materials they use to make set screws are usually hardened steel. But cheap set screws are soft and can be wallowed out easily. You can use the the long part of the handle to remove a set screw but insert the long shaft into the set screw and turn on the short side of the allen wrench. This may seem counter intuitive but do not over torque set screws. You usually have to remove them at some point and giving a gorilla grip to tightening gets you into to trouble.