yes because all that matters is in the end, how you look to an adcom member. 🙄 please. do what you love and everything else will be fine. if you want to do field work - do field work, for crying out loud!!
i spent two years doing field work (aquatic ecology) and i never got a publication out of it (just because you don't get a pub does NOT mean that you aren't a valid, contributing, hardworking member of the team... perhaps it just means your work was not accepted into a journal at that stage of the research), BUT ... i got some great experience, learned a helluva lot about statistics (you've got to process that data somehow to make it relevant to anything whatsoever), got nice and muddy, a bit of a tan, camped out at night, learned about science and solidified my belief that medicine, not ecology was the route for me. i've also conducted bench research - in an immuno lab, in a genetics lab, as a biotech research scientist.... in the end, research is research is research - it's scientific process, it's thinking objectively, it's being creative. don't - PLEASE don't - just do research for the sake of getting into med school, and do not choose the subject of your research because you think that it would look "better" to the adcom. no research team nor any supervisor wants this to be the sole motivation of a member of their group. if that were the situation on the team in my case, i would have just sent them out on the lake in a leaky boat. 😉 😛 kidding!
i'm sorry to be snippy about this and i'm not saying that your question is invalid, OP, but it's a touchy subject to me. i can't for the life of me stress enough for you to do what you enjoy and what interests **you** rather than what you think would look good to an adcom.