Since you already got good explanations of the differences between the Wizard and the Husky, I'll just tell you what we got, and why.
My dd is 32 months old, about 38 inches and 36 pounds. She's been in the 95th+ percentiles for both height and weight since 9 months old (even though she was a preemie who weighed less than 4 1/2 pounds at birth!). When we tried her in the Marathon, she had about an inch to go using the second-to-top slot, and the sides already seemed snug on her. I know, based on her projected growth on the growth charts, that she would have fit in the MA until at least age 5, probably to age 6, but that meant spending $250 for a seat that would last us about 3 years, 4 at the most. The Husky was $10 less, and we will be able to use it until it expires, so it made the most sense for us. Plus, dd has tons of growing room, and is totally comfortable in the Husky. There's a link to pictures of the Husky installed in my Accord and with dd in it in the Coffee Break forum, if you're interested in seeing how she fits in it.
We have it installed in the center backseat of a 1991 Honda Accord. There is enough room for an adult to sit next to it, but it's a tight squeeze. No other carseat would fit next to it, but if I moved it to an outboard position, I could easily fit another seat outboard...even another Husky.
It works fine with the belts that came standard on my Accord.