Sadly the majority of the sets are mix n match. I was reading though some of the club comics the other day. They haven't gotten any better with age, as the panels don't flow very well and they try and cram so many characters in (or very obscure ones) I don't know who is saying what, or what is going on. Either that, or I can't be bothered using my brain to work it out :p
When pretenders were out in the shops, I ended up buying a couple of the smaller ones, and they were OK. But I always thought they were pretty silly. Now that I'm older, I still think they are kind of silly, but appreciate them more for their campness (I guess).
In a way, it's a kind of evolution for the Autobots if they want to hide on Earth, but the Decepticons to 'hide' themselves as monsters it doesn't make a lot of sense. Even taking into the consideration that they might have been the basis as mythological beasts. If they were around that early, their robot modes alone would have made them monsters anyway.