My bunnies eat Sherwood adult pellets (timothy blend, not professional) and I’m very happy with it. It does have some alfalfa in it, but I don’t think alfalfa is BAD for adults bunnies, necessarily – it’s just that it’s high in calcium and fattening (I think?), so the majority of their hay intake should be something like timothy hay which is lower in calcium. But bunnies shouldn’t be eating a lot of pellets anyway, so they really won’t be getting much alfalfa.
The bag claims you can free feed it because it’s so “healthy”, but I would still measure and limit their intake – my buns actually got a little chubby since they love it so much and I had to cut down how much I gave them. These days, I give each bunny a heaping 1/8 cup per day (for 3 pound Holland lops).
I know some people really love Sherwood pellets because it supposedly cuts down on urine smell..? I can’t compare because I’ve never used another brand, but the only time I can smell my bunnies is when I’m actually cleaning their litter box. Seems to work!