I'm sorry to hear the earlier guests had such bad experiences. Maybe the quirks in service have finally been worked out. I came here the past weekend for a girl's weekend with my BFF. The interior decor was very clean and posh, more than you would expect from the exterior.
The women who worked on our services were very gracious and good at what they do (I had a mud wrap/dead sea salt scrub and facial). While they did recommend products (every spa does), they were low key about it. (I have been to other spas that were MUCH pushier than this one).
As for gratuity, none was demanded as we did not use a groupon. However, in both the U.S. and Canada, the understood etiquette on using a groupon is to tip on the retail amount. Businesses that put a mandatory amount could do so with more finesse, but they generally only do it because their employees have been screwed more than once.
I did not encounter the cranky male owner as the other guests described.