I had both saws and I have seen none of your work so I have no idea what kind of accuracy you are talking about that the Milwaukee can not achieve. Possibly you do marquetry level work with the Miter boxes.
I returned my kapex and am so very happy with the Milwaukee so I just do not get why you say you can not compare them. I find it very, very accurate, exactly what are you not finding accurate? I put the miter on 36.4 and make a cut and it is EXACTLY 36.4. I put the digital on 43.8 and the cut is EXACTLY 43.8. I can not put the Kapex on these angles and when I tried the cuts were never exact, always slightly off.
The Milwaukee has great dust collection the only other miter I have used like the Kapex, but the Milwaukee actually excels if you want to use a bag as it collects about 70% of the dust, the kapex is useless without a collector attached.
So I see many ways they can be compared. I owned both for a awhile and used them both for a long while before making my opinions.
If you are making judgment by making one or two cuts in a store great , I had the Kapex for a couple of months and the Milwaukee too, after that length of time I can not only compare the saws, but will keep my Milwaukee.
If anyone has used the Kapex for 60 days or more like I have AND used the Milwaukee for 60 days or more like I have, I would love to hear your opinions.
The kapex is more elegant in movement, the Milwaukee table and miter setting are better, the Kapex bevel is better, both collect dust well, the Milwaukee is better with only a bag for collection. I have had neither saw show any deflection that actually effect's the cuts in anyway at all.
My only note is comparing the kapex with its stock blade with the Milwaukee stock blade is a joke, if one does not replace the Milwaukee blade to the same quality blade on the kapex of course the kapex will cut with a perceived less deflection, many have tossed the Milwaukee blade in one day. Put a Forrest blade on the Milwaukee than test for deflection would be my suggestion.
The Milwaukee is NOT heavy I do not care what the weight says the way you carry it makes it VERY easy to move around and I am not strong by any stretch. I actually have really weak hands and fingers. To me a shop miter saw weighs 150 to 200 lbs and I wish I had the money for an industrial heavy unit like that. My Ridgid slider is FAR more heavy and bulky to move around than the Milwaukee. Granted you can toss the Kapex around like a toy.
I think the description is slightly off as far as reality and actual uses of these two saws, irrespective of what Festool may have thought or designed for that is not how those saws are used here in my personal experience here in the US.
I have never seen a kapex yet on a job site(I have already seen the Milwaukee several times), there are very few here that would bring a saw like that to the job site, I guess across the pond it is different. Actually most carpenters and trim guys here laugh at anyone spending what a kapex cost. I would hazard to guess that in the US most use the Milwaukee on job sites and the kapex in their shops and never bring the Kapex out. Most here that buy the kapex are either shop workers or hobbyists to date, maybe that will change, but I still see DeWalt 10 to 1 on the job sites followed by Makita and Bosch.
Per is about the only one I can verify that uses the Kapex like most saws are used on a job site and says they hold up so I believe it. It's just most guys are not Per and do not use the kapex like that. Maybe they should, but I have not seen it.
Here is the last inlay made with a few different angles, used my Milwaukee since the cuts were all relativley short, had no issues at all with the cuts not lining up.