I like Hau. Wally is the best rival there has been. The only friendly rivals that are bad are those of X / YCare to elaborate why? Not knocking your opinion down, just curious.
I feel like a friendly rival could be done well, but gamefreak simply doesnt know how. Hau and the XY gang being the worst offenders. Despite not liking his personality i feel the closest gamefreak got to a good friendly rival was barry in gen IV
In my opinion, it works better than the other. Blue is not bad at all but Silver is quite cringe. Personally, even better than friendly rival is laughing at the edgy kids, like Gladion