Ok, since you asked, here's my speel on the vans... sorry if I make you go to
Yes, there were tranny problems with Honda Vans and passenger cars. Auto trannies were and still may be the Achilles Tendon of the Honda family of cars. I used to work at Acura of Boston in the service department and the 1986-1990 Legends were notorious for trannies going bad. The rod that held the spider gears in the differential actually shot out (yes, out) of the tranmission in some cases. I've seen a 1" hole in a transmission case of one of these cars. The rest of the car was great, but the trannies had issues.
More recently the 4 speed auto trannies found in the Honda Odyssey (and other Honda products) in the 2000-2004 models had issues and Honda actually extended thier 3 year/36 month warranty to 77 month/109,000 mile on the trannie back then. I actually had a tranny replaced in my 2000 van I think like 4 years ago because the shifting was getting sloppy and it's still works great today. I still love to drive my 2000, even though we now have a 2012 Honda Odyssey.
My brother has a 2005 Honda Odyssey and moves a ton of DJ equipment almost every weekend and I have not heard of him having any issues thus far with the tranny.
Hondas will tend to be the most expensive of the 3. I didn't consider the Caravan but looked at Toyota and Honda vans and decided on the 2012 Honda Odyssey.
Toyotas have the bells and whistles for a cheaper price. The Honda will not come with the same things that on a Toyota may be standard, like driving lights, roof rack, etc.... small things like that. The Toyota had many different levels, Sport, LE and also has the option of 4 or 6 cylinder (Go with the 6, more power and the basically the same mileage) and also the choice of AWD which Honda does not have in the vans. Toyotas have seating for 7 or 8. 7 if you get the captain chairs in the middle row that recline and have a leg support like a lazy boy. Honda has seating for 8 in different configurations like the 8 seater Toyota.
Driving impressions: The Honda drives more like a car than a van. The Toyota, while having the sensation of a faster engine, is not as good around corners and feels more top heavy. The Toyota steering felt more twitchy at highway speeds. The Honda felt very smooth, quieter and more secure on the road, IMO. I felt like I could drive very fast very comfotably in the Honda, not the Toyota. Honda (I don't know about Toyota) has not only ABS and Traction Control, but also Vehice Stability Assist. Like I mentioned, the Honda felt like a car, the Toyota, a van.
The interior, albeit more buttons to play with, did not feel intuitive looking to adjust the radio or vent controls. Definately had to study on what to do. The interior on the Toyota felt cheaper too. Many people feel in the interiors of Toyotas don't compare as well to Hondas, material wise and also design wise. The Honda interio felt more intuitive, less little buttons to fool with and was very easy to navigate controls while driving. I gave up trying to adjust the vents on the Toyota after a while. The Honda felt very easy to navigate inside.
The middle row seat design in the Toyota is a very poor design, IMO. You have to sit in it to see what I mean. There is a hard plastic part of the side chairs that stick in to your sides if you sit in the middle seat and you're out of luck if your butt is wider than like a laptop. The middle seat of the middle row is a mixed blessing. It's built thin enough so that it can be folded up and fit in a side compartment in the rear cargo area. The bad side of that is that it looks flimsey and one may wonder about the strength of the middle seat of the middle row... Also, if you remove the middle row seat all together, there is an odd plastic tray that the seat sits in that reains there, weird design. The middle row seats slide in tracks in the floor of the Toyota which could present issues if wet salt filled snowy boots go in the Toyota, if the salt water gets in the tracks, there's really no way I can see of cleaning it out which could result in rust issues in the floor.
...which leads me to the rear row of these vans. The Toyota design looks flimsy. The Honda design by virtue of it's simplicity appears more stronger. The Toyota rear row is held up on pedestal legs that in the event of a rear collision, look like they may not hold up well.
Overall, we liked the Honda and got the EX-L. We wanted the cloth interior but actually the cloth seats in the Toyota felt nicer than the Honda so we up graded to the Leather (Thus the "L" in the model name.) and because of that we got a back up camera, satelite radio with a 2 GB hard drive, heated seats, moonroof (Love the open air feeling!) and other things other things. These newer cars come with so many nice gadgets now, like the power lift gate, etc.