Having sold those things for a few years, I'm not at all surprised to hear how your van setup went. It's actually typical for someone with good ears but not 100% knowledge of the field. And I would have sold you the Kenwood also..!
This might be a difference between the two, and why I maybe think some things that I do. - while it's always best to get a better Head unit to start your setup. In a car If you get good speakers and good amps then you can indeed manage with an average base point. A good amp to run your front and rear with both a HP and LP crossover, and a bridged 2 channel or Mono driving a sub box... Add that to even just reference level speakers and you'll get good sound. The amp is everything..!
Is also the same basic setup I have, and it's all hidden behind the stock panels so unless I'm thumping next to you, you don't have any idea what's inside. Of course I don't have the Kenwood though.
But maybe this "shoe on the other foot" exercise helps you understand some of the mistakes in my thinking... but also what I'm looking for. Because in this situation, I'm not really needing my truck setup, but more along the lines of your van setup. Only maybe with an Alpine Head unit instead of the Kenwood. - that's why I like the Marantz. But, I'd be fine with Bad, Monoprice... Whatever. I do like to lean to the Marantz though cause I have my Heos all setup, and frankly I just like em.
Anyway, between reading all those articles, all sounding exactly the same... I was considering what we went over in the thread, and I did think that a separate amp with more power would be a good thing. Cause it's what is do in my truck. And because that's how Marantz seems setup. I mean hell if they had their way I'd be buying 3 pieces (all the things that end in 006)
But now, I can see that an AVR will work. I just have to ignore all the reviews and advice I read online. I just have to satisfy this requirement I didn't even know I had, with the bass management business. And I have had separate crossover units in my trucks many times so you'd think I'd understand
If I'm completely honest though, I'm not sure if I understand yet why an amplifier doesn't always have some "signal out" for a sub. Is it really because people who but separates always have what we called "Tower" speakers when I was a kid. Meaning something big with a 12 or more built right into it..? I guess that would make sense. The big amp driving all the speakers. Tweet, Mids and Woofer. But I also thought that smaller profile floorstanding types were more in vogue now. Even for expensive stuff. Like those Keff 11s I think they are.