I can't remember what the weight of my BikeE AT was but the Sun is 41.5 lbs (
Sun EZ-1 Recumbent Bike - Bicycle Man). Neither one is all that light. One advantage of the Sun may be the much better gear range delivered by the standard 3 in the front and I think 8 in the rear gearing. My AT had a SACHS 3 speed hub and 7 speed cassette. The hub on mine broke and made the bike unusable. The repair costs were more that I thought the bike was worth.
I'd actually suggest neither one but look for an older long wheelbase or short wheelbase bike. Either one is likely to be faster and better for longer rides. I gave up on the BikeE within a few months and bought a used Linear LWB which weighs 29 pounds. It was like night and day comparing the two. You can read somebody else's impression here:
Why is a BikeE so slow? - BentRider Online Forums
There are a ton of BikeEs (no pun intended) out there so the prices are often really low in the $250-$350 for the more expensive AT model.