I like Vue 5i, but it does have some problems.

One (a very stupid one) is that you can't copy and paste materials without destroying material zones. Suppose you have imported a Poser model with bracelets and a necklace, and you have made a nice silver for the bracelets, and you want something similar for the necklace. You would expect you could copy the material to the necklace and then edit it a bit. You can't. Vue welds together instantly anything with the same material, so any new changes you make to the material will affect both items. There is a workaround, but it's tedious.

Another one is that with a couple of V3 figures loaded, Vue 5 leaks resources with every action until the program crashes. Even if all you're doing is shifting the camera around. Every so often I have to save, quit and restart. With a heavy scene this may be every twelve actions or so. Very irritating.