I like the series 1 mix, each fig has its merits in my book, yes some i like more than others, but isn't that always the way with any collection? I have some Star Wars figs that i like less than others, but they don't diminish the set by having them. For me variety is the joy of the series.
For that reason i'm less sold on series 2, the slightly lesser variety (no sci-fi?) combined with repeat elements that have had their moment of impact in series 1 makes for a naturally less exciting release... but i may yet warm to them. Only time will tell.
In fairness to Lego though, series 2 would have been designed at the same time as series 1. In effect designing 32 figs and separating them into 2 groups. Maybe it helps to view them as a collection of 32? Just a thought...
You can see this in the repeat use of Cheerleader/Lifesaver hair, Clown/Disco dude hair, Skater/Surfer hair and possibly a few other elements. A number of new moulds being used twice, mixed with existing moulds, made for a relatively safe product in comparison to just leaping headlong into creating 32 unique models. It makes sense from a business point of view, if you have no idea whether or not the series will be successful. (They might even have designed series 3 at the same time as 1 & 2. Which may mean even more repeat elements and 'old' figs).
This does mean there was no opportunity to gauge feedback until much later, I would imagine series 5 & 6 would be the most likely stage when feedback could be properly implemented. Maybe series 3 & 4 if we are lucky, if those have been kept at drawing board stage.
My personal hope is that series 3 & 4 will feature an increased number of unique elements, reflecting the success of 1 & 2, and implement some popular requests such as Canadian Mountie, British Palace Guard, Magician's Lovely Assistant (complete with 'feathery' leotard). Who knows, maybe they're ahead of us and already have the figs that complement series 1 & 2 planned for series 3.