Mono used to be like that, I started using it in the 60s when it first came out. Used my mothers iron until I got caught!! About 15 years ago they changed the formula and it sometimes works very well and sometimes not at all. That's when I tried Ultra and never went back.
I enjoy covering, I find it relaxing and don't feel like it should be work or have to be manipulated too much. I do need to do a few things differently then others but it is due to the climate here, really can be hot and it's always dry so I cure the Ultra before I put on the trim. I covered my last two builds during the winter or late part of fall and it wasn't hot enough to cure the covering. It has been warm here already and I took both my new planes out when it was close to 90 and so far I haven't gotten a sag or wrinkle in this Chinakote from Hobby KIng. At half the price and a 5 meter roll I really am sold on the stuff. It's even easier to put on then Ultra.