I have flown the new US Envoy and find the seat to be superior to the old United C seat. I cannot compare it to the new United C since I have not flown it. US's new seat is like LH's, and some people find it comfortable, and others do not like the angle for sleeping (slight incline vs truly flat).
Personally I like it a lot, and would defintely feel comfortable choosing it to save $250. Best of luck.