If your brakes are repeatedly having problems with shaking / pulsating, it probably is your driving habits. This problem occurs due to brake pad deposits on the rotors. That happens when you stop from highway speeds and then keep your foot on the brakes like at a stop light. Does this scenario sound like part of your normal driving routine? To prevent pad deposits, when you stop from highway speeds you should not let the vehicle sit stopped in one position. Let it roll just a couple inches and then stop again. Repeat this until the light turns green, never letting it sit in one spot for more than a second or two.

I also think your mechanic may have pulled a fast one on you. You can't just "order larger brakes" for a Honda Odyssey. The brakes are the same size for all versions of a particular model year of Odyssey, so you can't just order the brakes for a higher end model. So called "Big Brake Kits" are available for many popular high performance cars but the Honda Minivan is not a high performance car and no-one would market a big brake kit for it.

To fix your specific problem, my guess is the mechanic probably just put on a cheap set of pads. A knowledgeable mechanic will know that cheap aftermarket pads have very hard friction material which is less likely to cause deposits on the rotors. They also don't have as much "bite" as the OEM Honda pads. You may or may not notice this difference in braking - unless you get on the brakes very hard, you probably can't tell the difference. So it might be a reasonable trade off. Other benefits of the cheap pads is they tend to produce less dust than the OEM pads and wear at a much slower rate. The only downside is that for absolute maximum braking ( think emergency stop) the cheap pads will not stop the car as quickly. This is due to the reduction of the coefficient of friction of the pads plus the imbalance it causes front to rear in the braking system.

I hope the mechanic did not charge you a bunch of cash for supposedly putting larger brakes on your car. If he did, you were most likely ripped off.

I am not surprised. We have had two Odysseys. Both were excellent. Each time we went car shopping, we compared other brands including the Sienna. The Honda drove better than the others and was a better price for comparable features.

I suggest you avoid the 19" tires. They have short sidewalls which make it much easier to get wheel and tire damage. Plus the cost of 19" tires is obnoxious. You also won't get any performance advantage for the 19" wheels and tires - they are for looks only. Most likely, the 19" tires and wheels are substantially heavier than the 17" so you would actually get worse performance due to the increase in unsprung weight.