I have the Samsung (the ARM based) and love it!
Really depends on your needs. I rarely if ever do anything outside of Chrome on my Win7 laptop so it is great for me. Battery life is fantastic, it's plenty fast for basic browsing and Hulu streams just fine. STILL NO Netflix though.
The screen is matte and honestly not all that great. What I love most about it is I can pick it up and turn it on from dead to AF in less than 20sec! So it certainly helps with standby battery life.
Haven't used or seen the Acer but it just looks really ugly to be and much heavier since it has a fan, and I believe the screen is even worse. Hopefully you have a Best Buy or other store around you can play with one.
Lastly, I don't think it's worth the cost for a Series 5. I certainly wouldn't pay that much for Chrome OS.