Tweet*raises hand*
I've used both, and both are/were effective. I used proscar (finasteride) at 1.25mg/d for a few years. It did pretty much halt any further loss in it's tracks. I finally decided to stop using it due to sides: drastically diminished sex drive and a constant mental fog it seemed to put me in (this wasn't my imagination either).
I only used topicals for several months following and definitely lost ground. Panic set in and I went straight to Dutas (generic dutasteride). It too has pretty much halted any further loss. I've been using it only 3x per week so basically every other day in an effort to avoid/limit any sides. I've still experienced a lowered sex drive (although not as bad as when I was on fin) and another odd side that I've experienced is the appearance of dark circles under my eyes (LoL I have to use that L'Oreal Men's Expert Anti-Dark circle cream **** every day or they re-appear).
Taking dutasteride 2x per week is as effective as taking finasteride every day (atleast on paper). It's more potent than finasteride as it blocks both enzymes which convert test to DHT, but common logic would be to try finasteride first since it does have the studies backing it and it is approved by the FDA for treating MPB.