I know the value is good, but I am more concern with performance, sound quality and longevity. I am really not sure which one to pick!
RELIABILITY: I've seen just as many reliability complaints about Denon as I see for Yamaha.
I've owned 10 DENON AVRs that I bought brand new. None of them have ever had a problem.
Now I can't say the same for the refurbished AVRs that I bought and had to return immediately.
But they have been great to me when bought brand new.
POWER: Denon X4000 series can output 92W x 7Ch Driven into 8 ohms; Yamaha 2000 series can output 55W x 7Ch into 8 ohms.
https://www.soundandvision.com/content/denon-avr-x4200w-av-receiver-review-test-bench
https://www.soundandvision.com/content/yamaha-aventage-rx-a2050-av-receiver-review-test-bench
The older Denon 3805 (older 3000 series) is comparable to the newer Denon X4000 series. The Denon 3805 can output 170W (Dynamic Power output) into 1 ohm. That's right, it's torture test into 1 ohm!
SOUND QUALITY: As already mentioned, in Direct or Pure Direct modes, you won't be able to tell the difference. So the only difference will be in the Equalization (EQ) processing.
A lot of people care for room EQ. Personally, I don't care for any Room EQ (Audyssey, YPAO, Pioneer, ARC, DIRAC, Lyngdorf, etc.).
However, I absolutely love Audyssey Dynamic EQ (DEQ). I would never buy an AVR or Pre-pro without Audyssey DEQ.
So in terms of SQ, it comes down to the EQs. If you don't care for any kind of EQ, then it's a toss-up in SQ.
In terms of class vs price, the Denon X3300 is in the same class as the Yamaha 1070. You can get the X3300 on sale for $599 brand new. So the Denon clearly wins here in terms of class vs price.