Oh, the 435 kept up just fine power-wise as far as loudness goes --- in fact, it goes a bit louder than the 1070 at near-max settings. However, the sound quality was not there. Yes, by noise floor I'm referring to background hiss during quiet passages. It wasn't bad with the 435, in fact I didn't really notice it until I compared it to the 1070. A NAD I had previous to the HK was much worse though for background noise.
The 1070 has a nice setup for BM with the 3-way toggle for analog inputs. The 435 had better BM functionality for digital inputs, with the ability to set in on a per-input basis. The 435s AutoEQ was a bit of a toss-up, on the one hand it EQd the sub which really helped out with the low end, however I found that it had the effect of narrowing the front soundstage. It was as if there was a single big speaker instead of three front speakers --- this was nice in some respects, particularly for movies, but I preferred to not use the AutoEQ in the end.
I don't recall a huge difference in bass with the 1070, I thought the 435 was fine in this department and use a sub as well though.