Hey John--it won't cut into your fingers. I have been shooting a 12 strand 8190, which is the thinnest I've personally left on my bow for any amount of time (test string, plan to bump it up to 16 strands).
Servings come in larger sizes, but the problem with putting a fat serving on a skinny string is it's much more apt to slip. Padding out under the serving usually doesn't look good--makes the serving lumpy, etc. Double serving the entire length adds double the weight in the most crucial point on the string. I only do it when absolutely necessary, but when there's no other feasable solution I'll put a serving and a half--double serve in the nock area, single serve the rest.
I can't say it feels just like a regular sized string (to me--YMMV), but it doesn't hurt my fingers. I use a cordovan tipped glove, which helps.
Chad