This subject has come up before. The saw shown above appears to be very well closed in to capture more dust than are the TS 55 & 75. I am guessing the bearings are well protected as well.
I have never used any of my saws for cutting cement board, but have cut just about every other masonry product over the course of 30+ years. When i first started my masonry biz and was doing a lot of cutting with circular saws, i went thru about 4 or 5 of them withing the first summer. They all burned up from so much dust getting into the bearings. I finally visited my rental store and told them of my problem. We pulled every saw in the store off the shelf and checked closely to see if there was a reason why they were getting so much damage and if there was a saw on the shelf that might not suffer such problem. Every saw but one had an air cooling vent that was open beside the blade. One (Milwaukee 8-1/4) had the vent at the opposite end from the blade. I took that one home and it held up to everything (Masonry products of all kinds, nails, flooring with nails cut into) I could throw at it for the next 30 years before finally spitting flames.
I am pretty sure the Festool saw above has been well designed for such use as cutting cement board as well as many other cement products. If you are only making a few cuts for one job, I would guess the TS 55 & 75 would survive (with proper blades) and dust collection will be sufficient unless working in living space. If you are in a biz that you will be making 100's of cuts into any sort of masonry products, my thoughts are to have a less expensive saw than the Festools that are meant for cutting wood.
Tinker