I do not model in triangles specifically because quads make weight painting easier than triangles, but every mesh that I import is automatically triangulated in CC4. This and the automatic Tessellation make it difficult to accurately weight paint in CC3. Because it's triangulated, you can no longer select loops which makes weight painting way more difficult than necessary. I would like to suggest that when a model is being imported, that you leave it in quads, whereby you can use loop select to help make weighting easier. Once the weight painting is done, you can add a finalize step which then does the triangulation needed.

It would be better if Character Creator 4 had a finishing step that adds the triangulation --AFTER you've finished weight painting and tweaking everything. Modo had something similar back in the day called setup mode in which you could re-arrange joints and whatnot and then when you were finished you go back into whatever mode you were in previously. We need something like this in Character Creator 4. What I'm basically suggesting is changing the import procedure a little where the program asks you if this is a rigged/finished figure or whether or not you are setting it up so that you can more easily work with the mesh before finalizing it. Doing so would give creators back the loop select feature which is immensely helpful for rigging. Oftentimes I put in these loops in the things that I model so that I can more easily rig them but that all goes away when you bring it in. 

It's really sad because I remember when Reallusion advertised that quad meshes were a part of Iclone/CC. You can tick it off in the tab, but it doesn't put the mesh back to quads when you select the option. 

I have it in the feedback tracker if anyone else wants to support this:
https://www.reallusion.com/FeedBackTracker/Issue/Stop-Automatically-triangulating-imported-meshes_1