The only real benefit is some improvement in glare reduction. If you are in an environment where there is high ambient lighting, try removing some light bulbs, closing the window shade, using a halogen lamp that reflects light off the ceiling, etc. Another option is to purchase an after market anti-glare screen. This acts basically the same as a flat faced CRT
Flat CRT monitors are just as susceptible to geometric distortion as slightly curved CRTs. In fact you can argue that they have more distortion due to the refractive index of the glass creating a concave look. To flatten out the CRT face the manufacturers simply added more glass to the corners. This is why all flat CRT monitors weigh 5-7 Lbs. more than conventional CRT's.
If we remember our high school physics class, refraction's what makes a saucepan full of water look shallower than it is, when you look at it from an angle. Refraction in the monitor glass makes the phosphor layer look closer to the front of the glass than it really is, when you look at it at an angle.
Monitor glass is "leaded" - to reduce emissions. Leaded glass has a higher refractive index than common silica glass. The higher refractive index makes light split more dramatically into a spectrum increasing the apparent concave appearance.
Geometric distortion has more to do with the deflection yoke design, mounting and aligning to the CRT than how flat the face of the tube is.
Refresh rates have nothing to do with how flat the CRT is. The horizontal scan rate is the key specification that determines refresh rates.
Jim Witkowski
Chief Hardware Engineer
Cornerstone / Monitorsdirect.com