For me the MAS is a serious and steady revenue stream with about 15 apps in there. None gets more than 5 sales a day, but yet, this is a nice income.
I had to deal with bad reviews. It seems there are different kinds. The purely spammish ones are removed fairly easily. The crazies are another story. I never was able to have removed one posted by a guy for every app of the same type, identical (copy/paste) and inaccurate. Finally, there was that crash that suddenly happened with 10.10.3 and my app is now littered by people insisting on the crash.It is removed pending my finding what is exactly going on.
In all these cases, I have decided now that new versions will not be the same app. Pity for updates, but that is the only way to get rid of the baggage. I start anew with a slightly different name, and remove the older version with the bad reviews.
From the marketing forums around, it seems I am not the only one experiencing the total lack of response from Apple concerning unjustified bad reviews, and that publishing a new name is increasingly common.
The second app Store where I have business is the Windows Store, which soon will be open to Xojo apps with the Centennial Bridge, if all goes well. At present my apps are in VB for the Modern API. I have half a dozen titles identical to the MAS. Sales are at best 20 times less than the MAS.
The third one is the iTunes App Store, where I placed my first app a month ago or so. Just as Dave S did, I found out that my app was buried under everything including the kitchen sink, and never showed up at all with the keywords or part of the name. The only way to find it is by entering the exact name, “Elementary Letters”, but yet, for whatever reason, the first app to show in iPad is “Lowercase Keyboard”. Neither Elementary nor Letters appear anywhere in the description of that completely unrelated app, so I strongly suspect the search algorithm to be outrageously biased, probably with advertisement ranking. Sales are anecdotal, and would it not be for the real pleasure I got from discovering Xojo iOS while creating that app, I would have regretted to waste so much time on such a dismal result. To me the lure of the huge iOS market is over. It is probably great for Candy Crush and other games from brainless children, it is nowhere the kind of market for my apps.
Finally, I have a free app in the Android Play Store, to feel the waters. Unlike the pesky iTunes Store, it shows well and downloads abound, but I suspect anything with a price tag would not sell terribly much.
All in all, to me, the MAS remains the best place to sell programs.