Like everyone else here, I can not say enough good things about the Ulrta-dot. I have 2. One is mounted on my .44 mag while the other is mounted on my model 41.
Mount issues - none. The model 629 is factory drilled and tapped. The model 41 was drilled and tapped by a local shop.
Reliability - extremely reliable. It has held up to full power .44 mag hunting loads. I have seen the match-dot mounted on .45 cal. bullseye guns as well as .22's used for bullseye. Nothing tests your shooting equipment like competition, and I see a lot of competitive shooters using the Ultra dots.
Suitability - I'm not sure what you mean by suitability, but anything that helps these old eyes hit the target is a huge plus.
Accuracy - any of the red dots will help your accuracy as you only need to focus on the dot and the target rather than the rear sight, the front sight, and the target. You will still need a steady hold and good trigger squeeze. The dot does magnify an unsteady hold, but it is also more forgiving than improperly aligned iron sights. Interestingly, I just shot an ICORE match last night using a red dot for the first time. Up until now I had been using only iron sights. The dot allows me to be a little faster (now they can use an egg timer rather than a calander) with lining the dot up on the target.
I strongly recommend the Match-dot. I like the 4 different dot sizes. It is a well made and reliable product.