I have the 2 1/4 ton jack. I can't find it on their website anymore, so I'm assuming they're no longer stocking it.
In 2 years of light-to-medium use (lifting a Camry, mostly), I've had great luck with it. It's heavy, but only because it's built out of fairly thick steel. That's the reason I bought it. It never leaves the floor of the garage, so weight isn't an issue.
I give it a big thumbs up. I can't speak for the aluminum jacks---seems like a great idea but I just have a weird feeling about them---personal preference, obviously.
I'd buy another HF floor jack with confidence.