I would love to see pictures if anyone has successfully put up glass shower walls around their jetted tub.

When I was considering installing just a tub to save money in my remodel earlier this year, and to avoid the costs associated with a stall shower, I considered installing the air bath into an alcove with glass French doors. That way, you could open up both French doors when you wanted to take a bath, but you'd have the waterproofing necessary to use the bath as a shower.

The other issue with using the bath as a shower is that it's not recommended to use an undermounted or drop-in tub in a tub/shower combination. So that leaves alcove tubs or the more expensive varieties (like MTI and Hydrosystems) that allow you to design skits and flanges on different sides.

Here's an example: http://www.aladdinsglass.com/media/single-frameless-shower-doors/previews/French-Doors-for-Tub.jpg

I resolved all of this (except for the part about saving money, of course) by installing both a tub and shower stall. But good luck. I think it can be done, and I would have done it by using a Hydrosystems tub with a tile flange on three sides and a fixed acrylic skirt on the front with the glass French doors.

We have an MTI Harmony airbath/whirlpool combo tub at one end of a fairly large (16 x 10) masterbath. It's not enclosed by any type of door or curtain but I haven't found it to feel cold at all. It has an inline heater which maintains the water temperature and it is also a deep tub so the water is near, if not above, my shoulders. If anything, I tend to get warmer as I soak and usually have a large glass of ice water nearby (right next to a tall cocktail!)

Don't get a tub bigger than needed. How is the bathroom heated? Do you plan on underfloor heat? Radiant heat can be cranked up before taking a bath to keep the room toasty warm.