I agree about MaxPass. Being used to the 3 FP's at WDW (plus whatever dinky FP's you can get there same-day), I was awed last month at being able to FP headliner after headliner at the
Disneyland parks. I saw people waiting in the long standby lines and couldn't help wondering why more people wouldn't spend just $10 per person for a vastly improved touring experience.
I think this depends on how often you go, what your goals are. I'll be using Maxpass for the first time this weekend trip (flying out late tonight after work), looking forward to it based on everybody's reviews.
However, we're the type that get Deluxe AP's every other year, and I'm DVC so we stay on site about half the time and do somewhat longer trips. Therefore on my DVC trips we go in for EMH, hit the 5+ rides that are important to us in the morning with little to no lines, grab some FPs on the way out of the park and then settle in for enjoyment of the resorts and what is for us the main feature, the snacks. If MaxPass included a way to skip the beignet, ice cream, churro, and Food & Wine Festival lines I'd probably buy it every time. But we've never not gotten in as many rides as we've wanted with Extra Magic Hours plus getting regular fastpasses in the afternoon and evenings (we probably only do another 5-6 rides after those first 3 hours, half of which are the short-line ones like Mater's etc, but that's all we want). And so in a trip that is 3 days or more, we've ridden all of our favorites at least 4 times, all the rides we enjoy but don't love/absolutely need to go on 1-2 times.
This weekend we only have Sunday/Monday in the park and are staying off-site at my other timeshare since I'm out of DVC points for a bit, so MaxPass will be awesome with no access to EMH and the resort being a little farther away. Also having it be $10 is a different proposition for 2-3 people for 1-2 days than it is for a family of 5+ for multiple days (our last configuration, its fun to bring friends for the kids, etc, but it adds up! Snacks/meals can be and frequently are shared, MaxPass can't).
Personally I thought the 3FP+ in combination with the EMHs at WDW worked great, different system for a different style of touring. I'd love to see FP+ here as an option but I guess the technology is oddly proprietary to each coast.
To the OP: Totally get what you mean about Xmas Disneyland, I think Spring and Fall pre-Halloween are my favorite now for the combination of weather and not having it be all about the holidays. Born and raised Maui girl, but somehow still the heat of summer at DLR wilts me and the kids. My friends and I regularly talk about how we miss seeing the regular haunted mansion, Space Mountain, and just plain old Disney decor as opposed to the holiday themed stuff since the best time to travel for us tends to be when all of that is up (most of my friends and family's birthdays seem to fall during these times so is most often when we get to Disney).