They have different looks. I don't know that one is "better" than the other. I like printing color via inkjet because of A: the convenience, and B: the ability to make very selective modifications and corrections in Photoshop. Most precisely, the ability to deal with dust, hairs, and scratches. Of course, to get maximum results, you need a really good scanner.
As to your inquiry about Portra 120 vs. 35mm, I LOVE Portra as a film. I have made 16x20 prints from 6x7cm negs (my RB67) exposed through the first generation (non-C) 180mm lens and they'll knock your socks off - you can count bricks on the side of an apartment building I shot with it if you're so inclined. To make a fair comparison of the emulsion between 35mm and medium format, though, you need to eliminate as many variables as possible. Shoot the same subject, ideally with the same lens or at least equivalent lenses from the same maker (i.e. a Zeiss 50mm f1.4 Planar for 35mm and a Zeiss 80mm f2.8 Planar for Medium format, or a Pentax 50mm f 1.4 and 75 f2.8) so that the subject is the same relative size on each negative, get a high-quality scan done by a third party of each negative, and print them both. Then have a high-quality wet print made of both. I don't know how/where you are getting your wet prints done - the difference in quality you see (or lack thereof) may be as much a result of who is doing your wet prints and the equipment they have as it is a result of inherent quality difference.