I've tried both Altis and Chernarus and I've had similar behaviour with both of them. At first I thought it was mods and DLC and blamed it on Global Mobilization and disabled it, same with RHS. At the start saving and loading is very snappy and it gets slower and slower the further I progress. At the point where I drop off the reporter, I end waiting 5 minutes to load a save, and eventually the game just freezes when trying to load. The saved files do climb up to 140MB in size or so.