FWIW, my husband says his parents debated getting his tonsils out as a kid and didn't and he always says he wishes they did. He still gets strep a lot and constantly has a sore throat.
(I wonder if he could still get it done as an adult?) ;-)
Anyway, your kids may thank you later if you get them out!
Also I recently attended a nutritionist's seminar and she said recurrent ear infections have been linked to food intolerances. If your girls continue to get ear infections you might take them to their allergist (since you mentioned they've already been diagnosed with seasonal allergies) and have them tested to see if a mild food allergy or intolerance might be contributing to problems.