We have stopped here several times on our way to and from Bar Harbor.
We love their wines, on our most recent trip we left with 13 bottles to split between us and another couple.
Their Black Barstow and Gewürtztraminer are great. They also make a dessert (icewine) that is wonderful if that's your sort of thing.
The only negative I can say is that the employees doing the tastings (we have done 4 or 5 over the past few years) have varied both in knowledge and attitude. I'm quite sure working a wine tasting bar in Bar Harbor has its challenges, I have seen first hand how rude customers can be, so I have a lot of sympathy for the staff as it is. Also, I'm sure they get a ton of visits and it's probably hard to accommodate that volume of people graciously. But, at other area wineries we have been made to feel more at home by the staff. It doesn't keep me from visiting Bar Harbor Cellars and purchasing their wine but we do usually warn our friends that this isn't the "come on in, we're happy you're here!" sort of place. To give some contrast - on this most recent trip we spent 2-3 hours at a nearby winery as the owner showed us every detail of his operation and truly made us feel like we were welcomed guests. I don't expect this at every winery and surely Bar Harbor Cellars isn't the worst winery I have visited in this regard but it's worth noting.
Another thing worth mentioning - tastings here are free and the tasting we did consisted of 9 wines. That is hugely impressive in this day and age.
Overall, the wines are worth the stop. Smile big and be super polite and hope for the best.