Artesian seems to make a quality tub. As do D1, Master & HS. Bullfrog is newer company and there are a few people here that have them and they will tell you about theirs I'm sure.
As far as Artesian, it does seem efficient. I too live in the NE (NJ) & If I can judge efficiency of the tub on my past 2 months of ownership - I don't think winter's going to be too bad.
I have been in the water and the outside temp was low 70's and watched the temp climb from 99 to 101 from the pumps in the 50 minutes I was in the tub, I didn't expect that especially with the cover open. Closed the cover and the next morning it was still at the temp and stayed there for days. I know it's summer but it didn't lose temps with nights going into 70's.
Hope this helps!
