I picked up a box of the Mandrakes, I honestly don't see any major differance between the new resin and other brands available for self casting. It's a bit more durable than the resin forgeworld uses but not by much. Overall it's very nice stuff to work with much better than the metal, and the casting is quite good, most of the threads on other forums people are bashing and have posted have some really rough miscasts the likes of which I didn't see present on any of the blisters I was sorting through.
The quality is on par with FW stuff, with the exception that the mold lines are way better. FW models in my experience tend to have a lot of mold slip and really bad mold lines, the fine cast stuff seems to have fixed that pretty well. They do have some small bubbles on some of the models. On my Mandrakes one of the guys only has two toes and each of the models has some microbubbles on the right hand so the fingers are all slightly damaged. But given my experience with resin that's a very common occurance as the parts are really tiny, none of them are deformed enough to be unuseable but they will all require a slight bit of touch up with greenstuff.
One of the librarians I saw in the store had some issues with the power cables on his staff having some voids due to bubbles, but I looked at maybe 30 os so blisters and only two models had apparent flaws, so overall they are pretty solid casts. And that's coming from a very detail focused snob like me
In my opinion I think they came out well for the most part, but I am a very experienced modeller and used to the difficulties of working with resin. I'm not sure how great of a choice it'd be for the average 12-14 year old gamer however. I do realize that many of the kids may not notice or even care about the finer details as they are just getting the models to use for table top play and not high end modelling or painting. I realize that it may not have been a feasible option but I would have preferred if they'd kept the metal around for when you want a tablestandard model and then having finecast available for the more diehard modellers.
They were $33 which is a bit steep, the old models were $25 if I recall correctly? Being that the cause for the switch away from metals is that resin is cheaper to produce I'm not entirely sure why the price hike. They should have kept the price where it was at as they'd already be coming out ahead... but GW never misses a chance to drive their prices endlessly up. Finecast is a fairly solid product quality wise but I do think they are going to end up slowing a lot of their sales due to the higher cost.
3 out of the 5 models:
The microbubbles, and other normal stuff for resin like the weapons being slightly bent which can be corrected with hot water.