I have subscribed to Morningstor's stock investor, fund investor and
premium membership. In order to take advantage on their expertise, I
"invested" in 10-20 stocks on paper to see if they perform on the
average better then the Dow Jones. The results were: sometimes better
sometimes worse. On the average: for funds between Aug18 and 29 the
results were 1.19% less bad than the Dow Jones. The average For stocks
between Aug 1 and31 was 0.28% less bad than the Dow Jones.

I do not like to invest in funds since this involves either a long
commitment or a restocking fee if redeemed too early.

Morningsar does not make any recommendations for short sales.

Could anybody advise me what their experience was with Morningstar?

I've worked with Morningstar data for years, and I can tell you three things:

1: Their mutual-fund data is pretty good, as are their projections. 
2: Their stock research is full of interesting nuggets, but I don't
put much stock in their projections.
3: Morningstar, like most research organizations, looks for 12-month
returns. How their picks did over a two- to four-week period has
absolutely no bearing on the quality of those picks.

If you're looking for short-term movements, trading by the day or by
the week rather than by the month or year, stick with a
technical-analysis system.

V