Has anyone actually made money with these?  It seems like in these groups you are the dump.  They have their sell orders ready to go and the notice goes out and you fill their sell orders with your buys and you know how the rest goes. 

Have done this many times.  I usually don't sell low, but have been stuck in a few coins that I didn't really want to hold because price was rising and I thought it would go higher.  Then I hit that buy button and tank.   

What other coins do you suggest?  I see huge growth coming from Monero in the next couple of years. 

As far as smaller alt coins really like Sia.  Like the project and the team cares more about the project than the huge pumps of other alt coins.