First, let me point out that I do enjoy CMSF, it has good things going for it but of course, gripes rule - so I'm going to be griping about the stuff I don't like .
I enjoyed the previous 3 CM's due to their versatility. It was very easy to just pop in and start making maps and battles putting whatever I wanted in them as ridiculous as I wanted (King tigers vs Infantry in a city, Osterwinds vs T-34's - whatever!). With CM I am disappointed as it seems I have only a few units to choose from (as compared to most of the total armor, infantry and weapons in each army covered in WW2). Random battle building is more difficult - Apparently I can't choose exactly what my forces are - instead choosing infantry, armor, heavy infantry, etc - a step backwards IMO over the previous CM's. The lack of variety - another step backwards.
Now I know BF is in this to make money - but if it's $25 to get a few more units - several times (KaChing!) before I get even close to what I had with buying any of the previous versions... my crystal ball doesn't see any more expenditure on CM in my future. I got lured in to getting CMSF expecting it to be a gamewide improvement over CM. IMO - it ain't.