Over many years I have owned Ryobi, Jet, DeWalt, Makita & most recently Bosch the work I used to do was fairly heavy on Mitre Saws and accuracy wasn't the most important factor, the timber was railway sleepers, 6x2 joists, 4x2 joists, 4x4 posts, 6x6 posts and other similar sizes.
Out of the previous saws the most robust accurate and longest lasting was The Jet in fact it still sits under the bench with a broken guard but it does get used rarely for scrap or dubious timber.
The one thing that makes all the difference and can even turn a budget saw into a worthwhile bit of kit is the blade in the 25ish years i have owned Mitre Saws I must have tried over 15 different blade makes with many surprising outcomes.
Around 5 years ago I settled on Feud blades always negative rake for Mitre Saws and as Clogs mentioned all of mine go via the sharpener's before they get mounted on the saw
Current saw is The Bosch GCM 12 GDL it was bang on accurate straight out of the box and the massive plus lack of rear space it requires, The repeatability of the set angles is bang on
2 slight negatives are the dust collection isn't the best but mine sits in an extracted enclosure and the laser is a bit tricky to set up and needs adjustment if you have a different kerf blade, I don't use my laser and have fitted an LED shadow light which cost me less than £10 on line and was installed in minutes with a hot glue gun it needs no adjustment for different blades and doesn't need much setting up.
I replaced the the plastic insert place with a zero clearance wooden one which i change as and when required.
I have fitted a zero clearance fence made from MDF secured to both fences with a short replaceable insert between the 2 fixed fences which can be replaced when doing angled cuts.
If the saw was to break I would instantly buy a like for like replacement I am really pleased I made the investment
I have also brought a Bosch GCM 8 SJL which I use on site or if doing installs as the GCM12 is just too heavy to lug around and I have it so dialled in with infeed and outfeed tables with calibrated stops.