I did quite a bit of reading on this topic. The room is 90 sq ft, and calls for a 95 CFM fan. I was going to opt for a 150, but the duct work goes to 5 inches at that volume and I only have room for 4 inches, and there was already a 4 inch duct through my solid 18" thick brick wall.
I went with a Panasonic WhisperCeiling 110CFM - FV-11VQ3
http://www2.panasonic.com/consumer-electronics/shop/Building-Products/Ventilation-Systems/Ceiling-Insert-Fans/model.FV-11VQ3_11002_7000000000000005702
It's near as I can tell one of the best fans out there. Runs at 0.8 sones vs. the 4+ sones my crappy old Nutone fan was running at. I also splurged on a Lutron step-down timer for it.
The duct work was a bit of a compromise. The previous owner actually used the crappy white vinyl flexible 'duct' that came with the Nutone fan I guess, or with the duct running to the outside. It has been replaced with 4" rigid duct, screwed and taped. It does have 2 elbows in it, to take it up and over the recessed light fixture between the fan and the outside wall. But it only runs about 5 feet in total length, so it's fine, and there are no low spots in the ducting for moisture to accumulate.
The fan cost me $140 which was a good deal compared to the quiet ones at Home Depot. I've learned to shop there as little as possible. In Toronto, I'd highly recommend BOZ Electric up in Richmond Hill. I drive 30 minutes each way from my house, but it's worth every minute. I got my recessed low-voltage IC fixtures up there for $44 each. Super high quality fixtures (Contrast Lighting) and all made in Canada, including the 3.5" trim rings. The fixture over the shower is getting a shower-trim plate, which looks almost exactly the same as the other 5.
The Lutron switches were pricey, especially the dimmer for the low-voltage lights. It was $50, the timer was $40 and the regular dimmer was $30. But they're wicked cool
There's a dual-gang Nuheat thermostat going in the box just over from the switches.
Tape is up - guy is just putting on the first coat of mud.