V20 vs G5

One other thing to consider is price. The G5 will certainly be cheaper than the V20, especially with the G6 coming out soon.

I've had the G5 since last June, and I'm perfectly happy with it. In fact, I'm not getting the "itch" for a new phone now...

There's nothing wrong with the G5. I was happy with mine, however I was intrigued by the Quad DAC and I like the screen size because I played with a Nexus 6 P for a week.
 
I had the G5 before the V20 and here are ny thoughts on your comments:

Photo quality is similar

No way is the battery better on the G5.
The only normal reason the V20 would eat battery faster than the G5 is if the Quad DAC is being used especially at high output.

Lag and browser speed are virtually the same. I couldn't tell one from the other, however that is very subjective.
I'll see if I can do a side by side test with a G5 somewhere to confirm.

Yeah, my wife has the G5, so I'm next to one everyday and I can agree to what you're saying.