i have made 4 t-shirt quilts, i think they are fun to make. i use a lightweight woven fusable interfacing (from Joanne's but probably available most anywhere) to stablize the t-shirt stretch. the harley quilt i made had something like 54 logos on it (and it was not any heavier than any other quilt i've made)i used a low-loft poly batting because i didn't want any shrinkage from the batting, the t-shirts had all been washed 100's of times, so they were not going to shrink any. i made sure the cottons i used were pre-washed and dried (hot) so they would not shrink either.
some of the smaller pictures i framed with other fabrics, the big ones held their own didn't need framing. but i put it together on a design wall with all different size blocks; filling in where needed with checkerboards and other blocks and strips.