I like 1 1/2 inch blocks, as they finish at 1 inch and give that more delicate/graceful look you mention. I have made some log cabin blocks with half jelly rolls. It was ok, though not a great time savings for me. your 1 1/4 strips finish at 3/4 inch, which means you have a lot of rounds or smaller blocks. I also found it helped to spray starch so the strips were quite stiff--helpful when working with thinner strips.
RST