I am no expert on HT. Still replying to this since I incidentally got a demo of exactly these two combos that you mentioned. I am planning to buy an entry level HTIB - those with the AVR & speakers combo. I was seriously considering the Onkyo HTS 3400 since I believed this was the best choice under 30k. So last weekend I visited the Onkyo showroom in Forum Value Mall and got a demo of HTS3400. I liked it, in general. But while playing the Guzarish (Hindi movie) audio CD that I had carried with myself, I somehow thought vocals were getting a bit suppressed. The guy saw my expression and asked my comments about how I liked it and when I mentioned this - he played the same from another system - basically the Onkyo Tx 308 AVR paired with Pure Acoustics speakers. It sounder much better in that system. The store guy quoted 36.9 k for that (you mentioned 35k). If I decide to increase my budget to 35k, I would like to go for that combo unless I find anything better within that price range (I think that is unlikely). I also tried the HTS5300 - it had much more punch, definitely that lack of clarity on vocals that I noticed in 3400 was not there. But somehow, per my first impression, I still liked that 308 + Pure Acoustics combo more for nusic.
Do share where you got these quotes for. For 3400, I got 24.9 k as the final quote.