OPKs vs. Fertility Monitors

[geminigirl]

My doctor has asked that in addition to tracking fertility signs like BBT and cervical mucous, that I use some kind of OPK, in order to see if I am actually ovulating.  (We've just started treating PCOS with metformin, so before we seriously start ttc-ing, I need to find out if I'm ovulating.)  Does anyone have any experience with the "pee on a stick and compare the lines" vs. the Clearblue or Persona monitors?  I'm reluctant to spend the money on the monitor, but I think I'd find it easier to deal with than comparing the lines on the other variety.

Thans for your help.