I have 3 HT2s in a L\C\R configuration.
I am also a Helicon fan and seriously considered the 400's but due to my room, the tweeter\ribbon was above ear level, plus the price.
Lately I have had some extended Helicon listening time, between the 300s, 400s and 800s.
I'm not considering selling my HT2s, a friend has a friend who is selling the Helicons and we did some serious listening.
The 800s have better bass than the HT2s which should be obvious.
I think my configuration lacks a bit in that area in that I haven't taken the time to really dial-in my dual CS-Ultra subs.
Although the Dalis were not the first ribbon speaker I heard, after hearing them I knew I wanted a speaker with a well-implemented ribbon.
For a high-end that has endless extension, there's nothing like it, imo.
You could say that hearing Dalis led me to Salk speakers.
As far as comparing the HT2 against the 400, I like the HT2 better in the highs and mids.
I feel a more direct connection to the music. Cymbals, etc., are more detailed with better decay.
IMO, the Helicons have a bit more "forgiving" nature than the Salks.
This may or may not be an advantage depending on what you listen to and your preferences.
3 strong points of the HT2s, 3D imaging, detail and cleanliness.
Rydenfan, if your room allows for 3 HT2s instead of the HTC I would highly recommend it.
BTW, I have the sealed monitor version, not the floor stander so my bass is limited in comparison but
for my setup, the sealed ones work better.
No doubt you are getting the 400s\C200 for a great price so the decision is a toughie.
I can say I have no regrets as far as the Salks.
What's your associated gear?
The Dali ribbon is 10 x 55 mm.