First, I used to be a big fan of Fletch tape.
However, over time and a lot of use,I found Fletch tape to be a crap shoot, sometimes it works great, other times not so good.
I always glue both the front and back of the feather, on numerous occasions the tape has released, both partially and completely, between the two drops of glue. Often, on hot summer days, the tape will slip/slide into different positions. Also, when the temperature gets around zero the tape has failed when bumped, completely releasing between the front and rear glue drops. It seemed I was always fixing the feathers, adding extra glue (that looked like cr#$) to keep them in place. Life is to short to shoot ugly arrows, or an ugly bow.
Glue works. I have four Bitz's. For myself, time is not that much of an issue. I have chosen to go with the reliability of glue.