Hey Daniel
Thanks for posting! I haven't been, but I also like the look of the place. I had a Google around and found the following:
http://buddhisthermitagelunas.blogspot.hk/ - Their website, with address and phone and email details, as well as Dharma talks and various media.
Oddly, they have a Facebook page where it seems to be all about giving blood donations: https://www.facebook.com/pages/Buddhist-Hermitage-Lunas/234906763205922
And this German retreat listing website (http://www.retreat-infos.de/page3/page18/page18.html) states the following:
This is an affiliated Mahasi Sayadaw meditation retreat centre for those wishing to do intensive practice only. Facilities are excellent for retreatants - both male and female and ordained Sangha. The retreat centre is located in a quiet rural area about an hours drive east of Penang, close to the town of Lunas.
Sorry I haven't been, but I hope this helps!