I had never even heard of these until yesterday, but they look interesting.  The American Standard model I looked at was single-flush, 1.1 gpf.

For those who aren't familiar (like I wasn't), here's how they work -

Inside the tank is an air-filled bladder, with a specific volume of air.  As the tank fills around this bladder, it compresses it, increasing the pressure inside the tank.  When you flush, rather than just gravity, the air pressure of the bladder forces the water into the bowl.

I've read some reviews, mostly positive.  The one negative I've seen is that they are noisier than a "normal" toilet.  I have read that older models were very loud but current models are significantly quieter.

The prices seemed fairly in line with a quality low volume or dual flush - these seem like they could be a good option...

If you install a Toto Drake, you will have dual flush capability and great performance. We replaced our 'crappy' American Standard 2092 with Toto and could not be happier! At least not happier with a toilet:)

I also switched to Toto. I've used pressurized ones - they are loud. I also wonder, if one wants a pressurized toilet, why not just go with a commercial type (eg, Sloan Flushometer)? Then you can put a pressure tank elsewhere (nice clean look).

I have a lot of experience with toilets. I have 5 kids and a housekeeper and lets just say we need stellar performance. I have replaced four toilets in my house. The first was when I was naive and thought a good brand meant a good toilet and bought a Kohler that looked nice. Mistake as we still get clogs in that toilet.

Next I bought a Toto and although not bad, it does not have a forceful flush. For the next toilet I really researched and looked at the studies that rate toilets. I chose a Kohler pressure assist and then also got a Gerber pressure assist for the last bathroom that we remodeled. These two toilets are the best. You will probably never have a clog, which was my main priority. In addition, the water level and area in the bowl is very good and that means the bowl hardly ever gets dirty. If it does get a little dirty I just flush again and usually that cleans it out. I also bought a Gerber pressure assist for a rental property and that was a water saver (delivered by mistake) and I have never had a clog in that either. These 3 had the Sloan flushmate contraption inside, as I think some of the Gerbers now have their own brand pressure assist in the tank.

In any event, when it comes to toilets I would not try to save water and I don't go for the 1.1 gallon and rather keep my toilet cleaner and have better performance with more water. The two I have in my home are the 1.6 gallon models.

Now the only downside I can see to these toilets if it bothers you is that they are noisier and my guests have gotten startled and one even reported "he was afraid his privates were going to get sucked down" that's how powerful they flush. I personally rather take the noise of the flush rather than hearing my husband curse because the toilet is clogged for the twentieth time.

The Kohler we have is one of those taller ones and I am short (5'1") and prefer the standard height so just make sure you are aware of the toilet height you are getting.

Lastly, the Sloan Flushmate part in the tank is guaranteed for ten years I think after that it is not a big deal to replace that part in case it breaks.
The cost of these toilets is really reasonable at around $350 if I recall. For that price, you never will have to call a plumber and will have peace at home. If you would like to read the Canandian ratings yourself, let me know and I will try to find the link somewhere. It does not come up so easily on the search engines, but that study is frequently updated and lists every brand and model and tells exactly how many grams each can flush. Let me know if you have any more questions.
To sum up, pressure assist is definitely the way to go!

I agree with all of that. A Toto is good for most uses, pressurized is stronger (but noisier). Maybe they need to build the ultimate - a dual flush, one button pressurized, the other not.

I'd rather have any guests hear a whoosh rather than a "go baby go" chant from the bathroom. Next house will have these and a urinal for the bathroom off the entertaining area in lower level.