I bought 2 CVA Optimas for my kids and both have been trouble free. I've put close to 100 rounds through those ML's myself. They are simple, have nice balance, shoot straight, and they're not as spendy as a Knight or Encore.
The only gripe I have about them is the ramrod is to short, so they overcame that with a collapsible end that screws out.
BTW. They shoot 245 grn Powerbelts pretty nice.