Just expanded my RWM miniatures collection for things I hope to bring to Descent/Genesys and my recent purchases really bring home just how good the minis are- I can really recommend getting some of the RWM sets if you like the creatures/characters in them, yes you've got to assemble them but they're not loads of pieces and it's not too much hassle, there's only a few pieces to glue together, and yes they're unpainted but as with Descent minis you don't have to paint them unless you want to, of course they'll look more impressive painted- and they've been well designed for painting enthusiasts.
The other big reason is they do have plenty of potential to use with Descent- you don't have to glue the smaller bases to the larger main bases (the RWM army bases that sit in the army trays) and the smaller bases' sizes match the Descent tiles - most being 1x2 or 1x1.
I really like the RWM minis and I'm working on Descent ideas for them but it's not too difficult to come up with your own ideas and they open up some interesting new possibilities for heroes, monsters or lieutenants (and of course you don't have to go with expectation- maybe a character can be on either side as with some of the D2e lieutenants or an Uthuk character's on the heroes' side....)
The sets I've got most recently are the Latari expansion (I love the leonx, hoping to get one or two leonx sets too), Kethra- a really interesting character and I've got a bit of a soft spot for her mount in a tamable beast kinda way- maybe if it trusted you, nice 'doggy'...., the Beastmaster who's also awesome and the Uthuk expansion with the suitably chunky Ravos (a great way to bring a key Uthuk character and some Uthuk minions to your games and game kit).
Still some sets on my RWM wishlist so I'll likely be getting a few more, looking forward to making use of and eventually painting the ones I've got.
Even if you don't want to play RWM they're useful for adding to your Descent options/kit- each also has a terrain piece or two that could be used with map tiles for example.