I haven’t been but the reviews are very good. The trails are all signposted (balizados) and apparently easy to follow. It’s very “enduro” orientated (nothing to do with other MTB trail centres in Spain where trails are mostly on fire/dirt roads) so plenty of tech riding and singletracks (senderos). There’s nothing man-made, they’ve recovered and signposted many old paths in the area.
If you stay in one of the accommodations recommended in their website you’ll be supporting the MTB centre (there’s no public money involved in the creation/maintenance of the trails).
There are also guiding services and van uplifts if you are interested, again it’s advisable using one of the companies from the website.
In terms of other things to do….well you are in the Pyrenees, there are several National/Natural Parks nearby (Ordesa-Monte perdido/Agües Tortes).
I don’t think they have a dedicated English website, if you have any problems communicating with them let me know, I’ll try to help.