I installed EM2 and found out that it was incompatible with most of Raw files, ie Leaf, Fuji, and Kodak. Then I had a nightmare experience when I tied to remove the incompatible thumbnails from the catalog by selecting them and clicking on X, the thumbnails were removed and all looked fine until I started searching for the removed images. To my horror I found the EM2 had removed and binned all the original files while removing thumbs from the catalog, without any warning or notice. You can imagine how I felt looking at empty folders with 4 years of work gone! Fortunately I have backups of the original raw files but I lost all my edited and processed work which I only kept on local RAIDs thinking that they'll be safe enough. I lost months if not a good year's worth of work and I'm still working on re-cataloguing 4tbs of raw files. I don't were MS found this crap program from originally and obviously the engineers who worked on it never actually use it for real. Basically Buyer BEWARE!
It's a pity you had a bad experience, what a bummer. (on the PC) if I hit the delete key I get the option to 'remove from catalog' OR 'move to recycle', if I click the X icon I don't get the 'remove from catalog' option but I do get an 'are you sure' warning. On the Mac I get much the same thing, although I note that the dialog has the 'Remove' option highlighted by default, whilst it would be safer to have the 'remove from catalog' option highlighted by default just to be safe.
Lots and lots of people use xMedia, it's one of the best DAMs around - however, it is indeed flawed and Microsoft have been very tardy in ironing out some odd little idiosyncrasies. If it was 100% it would be perfect, as it is it's still worth using/tolerating because it's so much better than LR at being a DAM.
"found out that it was incompatible with most of Raw files, ie Leaf, Fuji, and Kodak" It's not compatible with Hasselblad 3FR too, but it is compatible with 100+ common files formats, it's just some of the MFDB proprietary ones it cannot work with, esp when there is no embedded preview in the RAW file.