I visit both WDW and DL about evenly, having been to
Disneyland sixteen times and WDW seventeen times!
I like 4-5 days at DL. I do prefer to stay onsite at DL but due to the cost, I will stay offsite, especially at the Hojo. While there are a lot of motels on Harbor and some are closer to the main gate than the Hojo, I think for WDW vets who stay onsite always for WDW, the Hojo is a good bet for offsite at DL. It has some grounds and just a more resort feel, although NOTHING like an onsite hotel at DL or WDW. It sounds like you are pretty set with onsite and frankly, I would stick with that if you can. DLR sends out pins and I get those, generally after I play around on their website. I NEVER get pins for WDW. So try that to see if you can get a good deal on onsite, it can make a big difference in cost for sure.
We have stayed at all three onsite hotels at DL, multiple times each and I do prefer the DLH over PPH. Now with the DLH having just had a refurb, that makes it even more attractive to me. DLH is much closer to a WDW deluxe than PPH and a much nicer pool area. PPH has a long slide very similar to the one at Boardwalk, however the rest of the pool and pool area felt lackluster to me. I still like PPH but prefer the DLH very much over it. I also love the GCH and it and DLH are both favorites of mine, even over the Poly and Boardwalk at WDW.
I think reading Hydroguy's links is time very well spent. They really lay out the differences between the two parks. For my family, we can't really pick a favorite. We will do 11 nights at WDW staying at CSR in March and do six nights in Disneyland in October, most likely staying at the DLH. We are equally excited for both! I also agree that its imperative that you do at least one weekend night at DL during offseason so that you can experience the fireworks.
Our favorite table service restaurants at the Disneyland Resort are:
Blue Bayou (for lunch)
Goofy's Kitchen
Minnie and Friends breakfast at the Plaza Inn inside DL
Naples in DTD
Ralph Brennans in DTD
Storytellers Cafe in the GCH
And frankly, we think the cs at DL is better than WDW's with Plaza Inn (its cs for lunch and dinner and the Minnie breakfast in the morning), French Market, Rancho de Zolcalo and Taste Pilots (at DCA) are our favorites.
I don't think full seve restaurants slow you down at DL. Everything is close to everything else, full serve dining is not the big draw like it is at WDW (no
DDP) so you while you need to make a priority seating (I think they still call them that at DLR if memory serves) is a must do for character meals and Blue Bayou (I really suggest you do lunch at BB, its inside the Pirates ride and while similar to San Angel in Epcot its very unique and your son would probably love it) in particular, you don't need to do it 180 days out! The restaurants don't fill up like they do at WDW and things seem to run quicker. I have never had to wait very long to be seated at any of your choices like I have at WDW. My son is 17 and loves Goofy's, he's been going since he was 8 years old and I think that is a great choice for boys. I think your son will love the rides at Disneyland/DCA and love the fact that your time in the parks, taking breaks, eating etc is all done with so much ease since you won't spend so much time getting around and waiting for your bus/monorail/boat/ferry. Its amazing how much you can get done.
But if you can swing the five nights/four days, I say go for it. You can take things at a good pace and have plenty of time. If you are going over Lincolns' bday weekend or Presidents Weekend, that brings in a lot of locals. We have been that time frame and were so glad we had five full days for those trips.
I think DL rides are generally better than their WDW counterparts, the charm and Walt factors are hard to beat and being able to easily walk all over the DLR are hard to beat. No busses or ferrys which is so nice. You leave the park and as long as you stay onsite or at one of the numerous motels nearby, you can be in your bed or hotel pool just a few minutes after you exit the turnstile.
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We watched airfare for quite a bit and it looked like airfare would absolutely kill us because it would be a multi-city itinerary with transfers, etc. We can drive to Port Canaveral with no problem and it's a looooot cheaper than flying. Did that just this September. I'll prob'ly keep my an eye on any 
