Herpstat Pro had the enter button too.The Herpstat II was the first multi outlet thermostat I designed. It was also the first to use a membrane faceplate. That sticker in the front actually has micro switches in it. Its pretty slick but you do pay a good amount per button. Also due to the smaller lcd at the time couldn't write a nice menu like the PRO and 4 have. So it was decided it would just cycle. This is fairly acceptable for the Herpstat ND but with two outputs worth of features on the II it does take a little time. However, I thought it was no big deal because I figured it would be set up and then left alone. I didn't realize how often people like to change the temps on the thermostat.
The Pro brought a huge screen and much better menu system. The 4 took the same lcd and then I tweaked the menu even more. Needless to say its pretty quick to change a setting.
I am looking at refresh of our single and dual output products adding in alot of the new tech I invented with the 4.No release dates on that though.
-Dion