there are differences in invisible threads---the nylon ones are (stiff) like fish line- when they break they have *pokey* ends...they can become brittle with time & melt with heat, stretches (and can break) while sewing
polyester invisible thread is softer- will take some heat, is not as apt to stretch/break. some people love it, some hate it- I use it on some machine applique projects- but i use a regular cotton thread in my bobbin - that's just me-
pick some up & do a little (experimenting) on a small project before *tackling* your quilt so you can see what it's like to work with & make any tension adjustments you may need. i think my most difficult part of using it is that fact (it's invisible) hard to thread the needle- other than that it's not hard to use. i generally try to find a silk thread to match as my choice before the invisible- but if that's not possible i turn to the invisible.