It really depends about what kind of kits you want to produce and who you target... Looks to me like BV is surviving pretty well, have not seen a Cub and a Mustang on his list, nor an F-15, yet

Proctor does not have either one of these planes, as quite a few other companies offering kits or ARFs and seeming to be quite successfull ( look there for example http://www.3seabees.com/planes.html ) without the eternal Cubs and Stangs...

If you target to be just yet another great planes, the advice is right, but wanting to do something a bit different is not necessarly doomed....

Bernard