James,
I've been very happy with the Technitop. Mine is an older version and does not have the moon roof option, but we recently got a new Technitop with that option and I'm really looking forward to it. Ours has taken everything we have thrown at it very well. We have over 300 nights in it in various conditions. The cover is starting to stress crack, but I think that may be due to the older mounting system. The newer tents have alloy rails for mounting. The only technitop specific issues I have seen are the extending poles getting fouled by sand. We have not had this happen to ours, but others have. The poles then jam and it can take a lot of work to get them free again without damage. But as I said, we've not had that problem. I highly recommend the tent, and Slee is awesome to work with. They will get you spare parts if you need them.
cheers