I had an opportunity to compare the Trijicon Bright & Tough Night Sights (just installed on my Glock 27) with the TRUGLO Tritium/Fiber Optic Sights on my M&P 40; here are some of my impressions.
Low/no-light conditions: both Trijicon and TRUGLO do very well with their green dots and appear to be about the same brightness.
Indoors: Trijicon worked better for me due to their white dots contrasting a shy bit more than the TRUGLO green dots. The white dots also had appeared more crisp. The TRUGLO green dot's brightness/contrast depends on the available ambient indoor light being picked up by its light pipes.
Outdoors: Hands down, the TRUGLO green dots just popped. They were really bright and this is where the light pipes really shine. Trijicon's white dots were more than adequate and were just fine.
Both the Trijicon and TRUGLO night sights were of high quality and definitely an upgrade to the stock sights of the G27 and M&P 40; I highly recommend either one of them, which of course is contingent on your particular needs.
The Glock 27 is my primary concealed carry and due to the nature of my work, the majority of life threatening situations will most likely occur indoors. So for me, I'm favoring the Trijicon over the TRUGLO. For outdoor run & gun events, I definitely favor the TRUGLO.
A note of consideration: the design of the Trijicon rear sight is squared off as opposed to the ramped design of the TRUGLO. Heaven forbid if my left (non-dominant) hand is injured during a firefight, it would be easier to perform a one-handed racking of the slide using the Trijicon rear sight against an edge.
Below: Trijicon Bright & Tough Night Sights installed on the Glock 27
Below: TRUGLO Tritium/Fiber Optic sights installed on the S&W M&P 40