Quad Castile verses Quad MVAE?

We just got our MVAE a couple of days ago, so I can't answer everything, but the battery back up is an option. $53 at my local Quad dealer for the wire, plus a deep cycle battery (about $90 for an Optima near me). Clips on the battery, plug into the stove, and it runs in a limited fashion for as long as the battery lasts. After Hurricane Irene and Sandy, not a bad option to have. Lots people around here were out of power for weeks at a time.

I don't have any regrets with My MVAE. I have had it for 2 years. I chose it for a few reasons....It seemed to quieter than comparable models (Harmon XXV and the Enviro M55), it has battery backup capability and it looks really nice. The only problems I have had are a couple of pellet jams that I cleared in 30 seconds by running a coat hanger up the drop tube and about twice a season I unhook the autoclean system and slide it back and forth manually a few times to knock off the carbon buildup otherwise the autoclean will start to stick. I don't consider myself to be very mechanically inclined so don't be intimidated by either of these issues. I love the programmability of the control panel although I wish it was more adjustable in terms of air flow and feed rate. I would purchase it again and I don't hesitate to recommend it.

I've had my AE insert since 2008 with no problems other than igniters. Maybe gone through 4 over the years and you can get them on ebay for half the price of the local dealer. One reason I bought the AE was the DC Battery backup. It has come in handy with power outages here in CT. I have two marine batteries which give me about 18 hours of back up. I also have a charger so I can take them to a friends to charge if power isn't lost in the area completely. I highly recommend based on my experience.

I bought a Mt Vernon AE this year (first year pellet stove user) and I can recommend it for all the reasons listed before. I was surprised and delighted that it heats my entire house, even during the cold snap in January. The auto clean feature is absolutely the weak link in this fine stove. I have to lubricate the rails about twice per month or the fire pot will stick and make a hellish noise when cleaning itself. I would rather have to clean the fire pot manually once a day or so. No other failures after burning over two tons of pellets. I also like the quietness - I run mine on Medium High.

Close to three years for me. I bought it for heat output and my wife approved it due to it's appearance. We have the mahogany color. I run it on high 24/7 because of the size of the house. It is primary heat with proPain as backup and I burn around 5 tons per season or a little more. Have only had one problem with it and that was because I wasn't cleaning the very bottom of the fire pot thoroughly. Dealer technician showed me the error of my ways last year (for 150 bucks for emergency service) and it has been running fine ever since.

This is our 1st year with the MVAE and have no regrets. It's a fine machine that puts a frown on the face of Mr. Propain. Only issue is my neglect in scraping the Carbon build up on the burnout. Now that I have learned my lesson, it just continues to keep our house warm and cozy.
Not a fan of the auto clean but it works per design. I have the mahogany also and it really is a very nice looking stove.