The Grand Caravan is the budget minivan that invented Stow-n-Go seating and still undercuts the Odyssey by thousands, but the 2008-2020 models have a transmission problem so predictable owners call them 'ticking time bombs.' The pump fails before 100k miles, the replacement costs $4,000-$7,000, and you're suddenly underwater on a van that was supposed to save you money. Buy a 1996-2007 model with the 3.3L V6 if you want the space without the drama, or skip straight to the Honda if you can't afford to gamble on a $6,000 repair bill two years in.
The Odyssey is the driver's minivan, quickest in class, genuinely fun to hustle around, and priced thousands below the Sienna, but it's aging ungracefully. Skip any 2018-2019 EX-L with the ZF 9-speed: hard shifts, hesitation in traffic, and transmission grenades at 93k miles even with perfect maintenance. Current models run the proven 10-speed and deliver on space, comfort, and value, but no hybrid, no AWD, and no rear ceiling vents (a dealbreaker in Florida with rear-facing seats) mean you're buying yesterday's minivan at tomorrow's gas prices. If you live somewhere temperate, drive spiritedly, and plan to sell before 2030's redesign, it's a sharp deal; otherwise, the Sienna's 34 mpg and standard hybrid make the extra cost disappear fast.