Way too many contentious claims. Yes, propecia is effective. How much more effective than spironolactone 5% nobody can say. Outside of testimonials, we don't have much research on it. But there are studies out there and the efficacy in terms of hair growth is almost identical to some propecia studies. Long-term stats we have to wait for.
So, to answer your question, people love pushing propecia, but if you only have small areas to apply hairloss topicals too and you are going to include at least minoxidil, spironolactone and copper peptides with Nizoral, you are combating it with an effective regime. My copper peptides have Saw Palmetto in them. So, my all topical regime stimulates growth (minoxidil), competes for DHT receptor sites on the hair follicle (spironolactone), reduces the formation of DHT via inhibiting 5-alpha reductase (Nizoral and Copper Peptides) and reduces inflammation. Propecia will not compete for receptor sites on the follicle. So, this is one angle that could prove very effective. On paper is should work as good as a minoxidil/propecia regime. The research suggests this as well.
Even more powerful, I have added Xandrox 5% at night with Retonic Acid and Azelaic acid. The latter is supposed to be a free radical scavenger and to also inhibit DHT formation. Retonic Acid aids minoxidil in terms of diffusing into the skin.
As can be seen, I have thrown a battery of substances at my hair and I feel confident that this will be effective, as effective as any other regime out there, save for some very shifty experimental ones. However, those are not an option for safety reasons.
If you feel comfortable reduces DHT systemically, go for it. Personally, I felt that my body changed (both physically and mentally) for the worse. I was on Propecia on and off for 2.5 years. I quit 8 months ago and will probably never use it again, unless something drastic happens with my hair. DHT does have a purpose in the body, namely, it helps with tissue regulation, among others. Because of my experience, I am off propecia as I do not want to offset my bodies balance.