Personally I don't see a problem with it - only the rice really (and if you use a lot of it, the soy sauce - I personally don't use that much). Fortunately for me the market I buy my 'takeaway' sushi from - Draeger's - recently introduced veggie sushi made with brown rice, seaweed, cucumber, carrot, radish and avocado. All good stuff - just add a protein and I'm in heaven
I like to save 'real' sushi for Free Day cos I like to have a LOT. The best place around here? Sushi Sam's on Third Ave - it's a little hole in the wall but they make AWESOME sushi at reasonable prices, unfortunately the whole Bay Area knows about it - so sometimes I order ahead and take it to go (Free Day indulgence: "Sam's Special" which is a hand roll containing rice, wasabi, a big ol' tempura prawn and special sauce). But there's nothing like eating sushi in a restaurant at the bar, when it's made fresh to order...mmm...