I have played classic Skyrim on ugrid 7, with 100+ mods, for some 150 hours of actual gameplay with a Radeon 5850 and an i7 730. Not even a single corrupt save game. The occasional CTD and that was all (RAM, I assume). No broken quests either. I also have 180 hours on Fallout 4, also on ugrid 7 since minute 1, some 35 mods, GTX 1070 and i7 6700k. Again, no corrupt save so far and if I had a single CTD, I don't remember. No broken quests either. Now I'm starting Skyrim SE, same rig as in FO4, same grid, some 50 mods. Just went from Riverwood to Whiterun, all ok. Curiously, the giant that the wolf guys kill when you first met them "poped" on the screen at the same distance it poped when I was using ugrid 5 some ten minutes earlier. That said, it's safe to assume that Skyrim SE should be ok at ugrid 7 if you have the rig to back it up. People who treat ugrid higher than 5 as a taboo haven't played with it and are biased, or didn't have the hardware needed to play safely. At least at level 7, quests are fine and save games are fine. The only downside is, of course, the FPS loss, but so far Skyrim SE on my rig is, near Whiterun, at 59-61 FPS, with dozens of mods at 2560x1080. ALSO: haven't tried with Skyrim SE, but on classic Skyrim you could revert ugrids to a lower level without hassle. You just had to load your game, alt+tab to Windows, open the .ini file, revert ugrids to 5, save the .ini file, go back to your game and save it. Done. Don't be mean to ugrids, they are our friends!