Avis ANC considers it a midsize car--no extra charge if you book a midsize and they have one available.
I'm not so sure I'd rate it high on acceleration. It actually did better than I expected it to (I had really low expectations), but when you really needed to gun it, it just didn't get up and move. I'd compare it to a 2001 Corolla that belongs to one of my family members, or maybe a base-model (2.0L) Dodge Caliber (which, thanks to its CVT, doesn't get up and go very much, either).
Also, I had heard glowing reports of its gas mileage--one person who had one in Colorado said he got 60 mpg driving up from Denver to his house in the mountains. I was a bit skeptical of that claim, but I was still disappointed when I found that my average was never more than 35 mpg, even when I reset the meter and made it a point to drive as soft as possible. I did rent it in ANC in November, and so the cold weather may have hurt the fuel economy, both because cars are less efficient in cold conditions in general and also because the engine runs at all times when the heater is in operation. (I tried to test it with the heater off while bundled up and with frost forming on the windows in the 5-degree temperatures, but I could only stand it for 15 minutes at best. I didn't see a huge improvement--certainly not 50 mpg.)
I think it'd be a fun car to toodle around in. In my current stage of life, the size would work fine, and the price is within reach, though I'm not sure I could justify picking it over a similarly-equipped non-hybrid car. Given a few more years and a better income, and given that I'd want a hybrid at that point, I'd be more likely to choose a Camry hybrid (fully decked out, of course), which in my minimal experience with it, felt much more refined and gutsy. (I'm in the process of convincing my grandfather to go for a Lexus LS600h, but he's not yet convinced that it's a wise use of finances, and he's probably correct...).
If it were available at no extra charge at an Avis location, I'd probably take it in a heartbeat over a Caliber or Focus or similar, though I'd probably choose a G6 or a Sebring/Avenger with the 3.5L engine over the Prius--gas mileage is less important to me than the coolness factor and driving experience. If my options were between an intermediate Caliber or Focus or a $5 upgrade to a Cool Car Prius, I'd probably take it, but much over $5 and I'd probably be likely to decline the offer.