Yes possibly as you say, possibly they will be better then MDF, drawer slide and skate bearing routers, etc. I think more like on par with them. For a larger format router I am not convinced at all. I am not a expert and only have 3 machines from scratch using V rails, but what I see in my shop the Vrails in aluminum in the makers current size is not going to cut it. Then again we can be talking different animals here. I could never imagine replacing my current set ups with aluminum V.
The wheels are a cause for concern, yes I agree and that in itself rules out the maker slide becasue I do not think using steel bearings is advisable on the aluminum Vrails or they may not last very long.
Another issue with the 3 builds I have done with V rails is that I could never clamp down on the maker slides like I do on the steel rails. I am sure I would distort them getting them tight enough. Not to mention the small size of the Makerslide in this format is definitely to small for the larger spans. Possibly a larger model maker slide needs come out for a heavier duty router, still aluminum is not my choice for the vrail.
I have heard some are taking the steel V rails off their machines in lieu of the maker slide, that is weird. The steel is better! The all in one Makerslide just makes it easier to initially assemble and allows a plastic bearing for possibly less noise, but the maker slide is not any better than the original build. I would say people are exchanging a more durable set up for a less durable set up. Go Makerslide for a new kit, but to retrofit and replace, that makes no sense to me.
No one can convince me that those aluminum V rails are durable enough for a router unless the router is a very light set up. And I do not think bdring ever implied the maker slide was for anything more than light weight use. Start slapping on 2.2 kw spindles and that is not light use.
Why even try to go with the aluminum V rail when steel V in existing extrusions are quite a good deal when you compare attaching the Vrail to an extrusion or aluminum block. I could see the need for the Makerslide for a laser application of this smaller size, but that's as far as I see its usefulness ie very light weight duty.
Now if someone were to set up a larger router and run the maker slides for 4 years with no issues then I would be convinced.