Hi,
All Health Sciences Authority (HSA) - approved generics should work well and are generally non-inferior to the originals.
Stick to propecia if it has worked well for you and you are willing to accept the premium price over generic finasteride. Propecia gives patients the assurance of proven efficacy from numerous well conducted studies and its side effects are well documented. Consider switch to generic finasteride if you are after value.
There are no head to head comparisons between the 2 products and opinions regarding which is better will only be subjective and rather variable.
Hope this helps!