It's not that bad really. It takes more time but it's actually easier to get lined up than a topper, if you ask me.
Lately I have been taping the piece on the back and sides, making sure to start peeling the liner corners when the unit is OFF my head. Then I put it on my head and line it up. next I lift the back only and peel the liner off the tape. Sometimes I mist with 99%, sometimes i just tack the sucker down.
Once the back is secure I flip the piece back so it is hanging off the back of my skull. Then I do a strip of glue down the middle of my head. When the glue is dry I mist it with alcohol and pull the piece back up and stick it down.
Next I peel the tape off the sides and tack it down. Lastly I mark out my glue line at the temples and hairline, then I clip the hair back and apply glue. From there it's just a matter of letting the glue set then flipping the remaining lace down.