UTX, XG, GEX, FEX overlap

There's an alphabet soup of add-ons emerging for FSX from folks who did a wonderful job with FS9. I just bought and installed UTX and have had ASX and XG for some time.I would like the benefit of some experience from someone who is using all or most of the above; what features, particularly where they overlap (e.g. cloud textures, etc) are you using? How do you load them to keep from inadvertently overwriting a change you want to keep with an earlier change from different software? Basically, how compatible are they and do they "play well" together?