not all invisible threads are created equal; nylon melts, monofilament can be pokey and seem like you sew with fish line; some is move pliable than others. best way to tell if it's going to hold up to use? when i was doing my sons quilt i had 3 different invisible threads, i made 3 sandwiches and stitched all over each one with a different thread...then i ironed the crap out of them, then i washed them in the washer, and dryer...took them out and checked them over...
then bought some nice verigated thread and quilted the quilt.
long story short....try out the threads before you commit to a whole quilt.