I've used them before, they were fine for us. Pretty sure it was a ResortHoppa bus they used. Voucher had a Spanish number & a British number, could phone either one, to confirm pickup for transfer to airport 24 or 48 hours before. I asked hotel reception to phone the Spanish number in case it was a Spanish speaker but it turned out to be an English lady so reception passed me the phone. Lady gave me the time & advised we be there 15 mins early. Think they turned up bang on time.
Edit: Just checked & it was a few years ago in Fuertaventura but would imagine they're still using the same system.