I was never a big Van Halen fan. In my formative years, I bought VH1 and Diver Down, and I disliked most of what I heard off of 1984.
That being said, the 5150 material sounded nothing like what Van Halen had been. The songs were far less hard-edged and way more polished and "poppy." However, when it came out, I was starting to expand my tastes beyond the "if it ain't heavy (or Rush), then it sucks" mindset that I had during my last couple years in high school. I don't think I bought 5150, but I think I made a cassette copy of it from a friend's tape, and I generally liked it. Looking at the track list now, I can only remember Why Can't This Be Love, Dreams, Best of Both Worlds and Love Walks In, and I like all of those songs except Best of Both Worlds, which I didn't hate but didn't really care for.
Never got into OU812, and those two albums really felt like a completely different band than the DLR-era band.