My 46g bowfront is pretty similar, dimension-wise, to a standard 55g tank (well, 3/4 of a 55 gallon, at least). It's about the same height (the bowfront is an inch or two taller), and the "depth" (front to back) of the 46 goes from 12" to around 15" and back to 12", whereas a 55 is a constant 13".
Bowfronts seem to be like other tanks in most respects, but I can think of four things about them that may be worth mentioning:
1) The tank and top/canopy tend to be more expensive than standard tanks.
2) It's more difficult to build your own canopy, obviously, becuase of the curved front.
3) They tend to have dark spots, for two reasons:
a) If you get the standard (mostly opaque plastic) hood with single strip light, the light configuration puts the bulb close to the front of the tank, and the ... slot ... you put the light strip in blocks some of the light.
b ) Just because of geometry, the middle of the tank, near the top (i.e. the widest part of the "bow") tends to stay a little dark. Sometimes fish swimming in that area aren't very well illuminated.
For those reasons, I'd strongly suggest that if you get a bowfront glass, get the top made almost completely of glass -- it'll allow you to use either a double-tube strip, or a second (slightly shorter) strip to "even out" the light.
4) Those magnetic algae "scrubbers" may not work as well on a curved surface as they would on a flat one.
In short, a bowfront isn't much different than a standard tank, as far as fish health is concerned. It basically boils down to: bowfronts are more expensive, but most people think they look better.
