I've not seen any Santi Seam issues. They did have an issue with Zippers, but that was TiZips fault, not Santi...and they covered the issues. We did see some issues where neck systems weren't prepped properly, and would come out, but that was rectified a couple years ago. We are a large Santi Dealer and repair center, so we've sold a lot and serviced alot. They probably have the best seams, they use escalator glue, and good rubber tape to seal up the suits.
Ursuit had issues mainly on there breathable suit, and the 4th Element they built for them. They too, fixed those issues and are running solid now. They mainly use Melco tape for their seams. We are also a large Ursuit dealer, and repair center, so we have lots of experience on how they come and go.
Rofos - Love the fit, wont' do custom sizing though, but will do a couple mods. Their suits are really nice, and the cut is good as long as your more athletic. They also use mainly melco tape for the seams. Have had zero issues, with Rofos, but we don't sell as many in the US to have the same quantity/quality perspective as the others above. We might be the only ones selling Rofos in the US, other than the UTD brand which is rebranded Rofos.
Issues with suits is why we offer a lifetime warranty, that covers everything that can go wrong with a suit. I'm not sure if anyone else offers such a thing, but with our large repair center, it allows us to do that. Most suits will never have an issue outside of normal maintenance (seals, zipper, occasional hole) which our warranty covers, but it also covers seams, boots, and everything else. I would ask your shop if they offer one when purchasing a suit, and go for it for the piece of mind if they do. Again, most suits will have no major issues, and if they do, the manufacturer will stand behind it. That doesn't mean your dealer will push the issue to get it fixed, or have the influence to ensure your taken care of, but we never have any issues when it's needed...although, most manufacturers have us do the repairs anyway
Buying the right suit, from the right place, with the right fit and features for YOU is crucial. That is why we sell almost all brands, so we can help you find the perfect suit for you vs. the 1 or 2 brands most other shops push.