Last year I won a couple of sprues of Mantic Northmen in the club Christmas raffle. In an effort to try and avoid having left them unused for over a year, I dug them out and assembled them.
There's enough variety to get by with ten models, but you would start getting some repetition in units of 20 or more. Which is fine for mass battle games like Kings of War, but less useful if you want loads of variants for roleplay purposes, for example. There's minimal merit in getting a second box for some variant assembly, for example.
Easy of assembly was pretty good. Single piece bodies, weapon and shield arms, and heads all go together OK. A couple of the head - body joins look a bit . . . odd? But broadly, they're fine. Mantic had some absolute horror shows of assembly in the early days, but they seem to be past it now. They're intended for ranking up, though, and I have no idea how some of these would . . .
The lack of variation means that there's very little waste plastic. You can assemble them with spears or hand weapons (I went with a mix, because skirmish), but that's all that's left over when you're done. I get the impression this will help a bit in keeping waste, and therefore costs down. These Mantic sprues are efficient - they do exactly what Mantic needs them to do, and no more.
There are quite a lot of mould lines - you can see on these foxes where I utterly missed them and need to do a little doctoring. As well a not quite as flush as they could be joins for some of the legs. That said, getting two cute foxes in with the infantry box is a nice touch. I seem to remember Mantic have a tendency for adding a couple of critters in with an infantry sprue, and I like that. It uses the space to give you something, and it's something you can use, not alternative arms that will end up having no body.
All in all, I quite like this kit. There's a definite time investment in mould line clean up, but that's not exactly uncommon with older Games Workshop kits either.