I've been buying software again and thought I would mention some things.
Chessbase 12 and Megabase 2014: Basically, I was a little upset that Convekta's megabase seems to be missing games. Basically, if you look at the beginning of the base, it's clear that the chessbase database has many more of the early games than convekta's does. Also, when I would read chessbooks and look into the database to find the game record so that I could follow along, I would come upon games that were missing. This included games from tournaments like Linares which it kind of seems to me like such a big base should have. It's not so difficult to enter these myself while I am going over the game, but somehow it seems disappointing that this base isn't more complete. These were some of the things that led me to try chessbase 12 and the megabase.
One thing that can definitely be said about chessbase is that it is much prettier than Chess Assistant. Chess assistant looks like a program from the 80's or 90's not one from after 2010.
On the other hand, I have some complaints about chessbase. It seems to me to be buggy. One of the most major things that bothered me while using it was that I was copying some of my own games and chessbase somehow messed up and changed the names of one of the players on several game records. This seems like a serious problem. If I can't trust the accuracy of the copying function then I will have a hard time using it and will constantly be worrying if something has been changed by the program.
I also have a complaint about the opening reference function. In general I found the tree function much less helpful in chessbase than in chess assistant. One of the things I like most about having a big database like this is navigating these kinds of trees back and forth and seeing what the different options that have been played are. I like to do it both with megabase and with my own games database to kind of review my repertoire and look at success rates. The first thing that is not so much a bug as it is just different implementation is that in chess assistant I can actually call up a window with the tree in it that is separate from any game. Then I can navigate the tree and easily call up a list of games from any position. It is obviously possible to do these things in chessbase also, in fact there is usually a small window with a games list automatically registered next to the tree window. It is also easy to order this list by elo of one of the players. Still, in general I did find it less convenient more akward that I couldn't call up the tree independent of a game, and that navigation of the tree automatically writes variations to the game. I prefer the chess assistant format where the tree is separate and can be independently navigated and then when I'm ready I can call up the list of games.
Another problem with the tree was that it didn't seem to be accurate. I have been trying out the English opening lately and recently after getting my games into the databases I was looking at the tree of my white games, and at the first move there was no c4 move shown. I forced c4 on the board and then the list of games showed up, but when I left and came back the same problem happened of no games showing up for c4. In this case I only knew it was inaccurate because I knew I had played those games and that I had just loaded them in the database. So again, it's a confidence issue. It seems that if this happens in a situation that I know it's making a mistake then it is probably going to do it when I don't know it's making a mistake and that would be worrisome. To be fair under the opening report function instead of the opening reference section it was showing those c4 games but still that's a pain in the ass.
Another complaint is that when navigating the tree, the success rates stay the same. So they show a percentage score for white whether it is white or blacks move. I much prefer the chess assistant format which shows not just a percentage but actually a graph for every move that shows how many win lose and draw. And something I really like, it changes when it is black to move, showing the wins as black wins, so when you are looking at the score you are really seeing the score for that move, rather than the score for white in that line.
Lastly I would say the tree is slow because it has to search every time instead of having the info prebuilt like in chess assistant. So every time you make a move, you have to wait awhile while the tree list loads and gets the true number of games registered for each move.
One more thing about the tree actually, sometimes when you are navigating the tree instead of showing the most common move at top, it flips the list and shows the least common at top. It's annoying.
Also, in terms of managing my own games, I found the process of creating a "my games" "my white" and "my black" databases much more of a pain in the ass in chessbase. I feel like I spent a lot longer trying to get the games arranged to my liking in chessbase. While it takes a minute in chessassistant it is basically pretty easy. One thing that helps here is the cascade setup where I have a number of small windows with game lists that are easy to move around and jump back and forth with especially with the database list window on the left.
Another complaint is the filter function on the database. If I go into position search and setup the first move of the English opening (maybe not the best way to do it but I was looking for alternatives to the tree function) and then search, I end up with an empty list. I have never figured out why this is. My only guess is that somehow it is too big a list of success, but that's just a guess and I don't even know if it makes sense.
I do remember some sundry other error messages and annoyances with chessbase but they're not big enough to mess with.
A last point I converted a chessbase base to chess assistant format a couple of years ago and found in the tree that there were many games that were registered as ending without a move. At the time I took that as evidence that the conversion process had been faulty. This is not true though. There are many non-records in the system. I just looked and found 4,600 games that ended after white played 1e4. In the base I converted before I found 60,000 games that ended with no moves at all. It's hard to see this in chessbase because it doesn't want to give you a tree for the first move. So it seems I might go through the process of converting again, although it was a major pain because the file was too large to handle as one thing and I had to do it in pieces last time.