Just started FTB Infinity and got the basic Wyvern Armor.
Two things I recognized about the armor:

• Jumping out of sprint feels really wonky, since the jump slows you down significantly
• The Boots seem to drain RF even if you have other Items that prevent fall damage, e.g. Extra Utilities Angel Wings

"Jumping out of sprint feels really wonky, since the jump slows you down significantly"

Yea thats something i find rather annoying aswell but i think its going to be a pain to fix.

"The Boots seem to drain RF even if you have other Items that prevent fall damage, e.g. Extra Utilities Angel Wings"

It actually uses a small amount of RF when you jump. (Such crazy jump height dose not come free)