I'm going to cover Kreons in a few days, but before I do I thought I'd look at the previous Clone line which featured Transformers: Robot Heroes.
Robot Heroes was a line of cute 'kid-friendly' PVC Transformers, featuring robots from all eras of the franchise. G1, Beast Wars, Bayformers - all were present here. They didn't transform and articulation (which varied by robot) was generally limited to shoulders and head.
Their main selling point was that they were cute and you could stuff a load of them in your pocket.
Earlier I called this a 'clone' line. I say this since companies like copying what other companies are doing. If they see something is selling well, then they'd quite like a piece of the action too. A whole bunch of different companies started selling figures similar to these (but based on other franchises, eg Doctor Who) at about the same time. I think Hasbro actually started this one, however, with its Galactic Heroes (Star Wars) and Superhero Squad (Marvel comics characters) lines, so they can be forgiven for starting one based on its other popular toyline.
They were initially sold as 2-packs, however later they began selling as 'blind' single bags as a Tesco exclusive. There were also a few larger packs, featuring 5 or 6 characters.
There is an Issue with these and one you have to get over before you can enjoy these: they don't transform. There are some people who will insist that Transformers that don't transform defeats the whole point of Transformers and will hate these guys for that reason.
If, however, you can get over this point then these guys are great. They look like the characters from the original Transformers cartoon - someone which none of the transforming Transformers have ever done. I also love the fact that they cover all eras.
My personal niggle is the scaling. When the line started they made everyone the same size. This meant that Unicron (who should be planet-scale) was the same size as everyone else. I could accept this at the time, but then they released a larger Fallen figure for the Revenge of the Fallen film. And thus made Unicron look...well, tiny. The Marvel Superhero Squad line was also getting much larger figures (Sentinel & Fin Fang Foom, for example) and yet Unicron remained small. Predaking as ickle.
But apart from this, I love these guys!