I have a DHD as well as the One X. Both get poor reception in my house, so I have a Vodafone Sure Signal to boost it. But without the SS, I would say that the One X is very similar to the DHD, both vary from "no signal" to 3 bars out of 5. The signal fluctuates so rapidly that it's hard to do decent comparison, even with the phones side by side, but neither goes above 3 bars, and most of the time I have 1.
Worth bearing in mind, though, that the DHD is 18 months old and has had several radio updates in that time. I can't be sure now, but I think reception in the house was worse when I first got it. Hopefully the One X will see radio improvements as well in future firmware updates.