Don't ignore the E170 - just a shorter version of the 175. Haven't flown on a mainline E190 yet but it should be about the same as it's just a longer version of the 175.
There is one thing to keep in mind. US is putting in a FC section on the larger Express planes like the 170/175 and I don't know if that'll affect coach seat pitch, which SeatGuru lists at 31-32 inches. The mainline 190's already have FC and coach has a 31 inch pitch per SeatGuru. Except for that, the wider fuselage does make them more comfortable than the CRJ's. For domestic coach, I think the 170/175 have been a favorite with the FF's from the start.
Jim