I faced the same choice back when I first started looking into buying my BP. I think the answer is that both of them are great products, both reliable and well-liked by those who have them. I voted Herpstat only because that was what I ended up purchasing and I LOVE it. It's user-friendly and the unit is on the small side, which is nice. I've had no problems and definitely recommend it. However, I wouldn't hesitate to get a Helix, either. If I ever need to buy another Thermostat, I'm going to be getting a Helix so I can get a feel for both types
