For a carry gun, and a HD gun, they are what we want.
At least, here's my thinking on it--
1. My background is in 'marksmanship'--those are the deeply-ingrained techniques I have. IOW, I unthinkingly seek a good sight pattern. That's a real counter-habit to good / fast combat shooting.
2. My eyes are older now--that dot, when it's available, really works for POA shooting. However, it isn't the sole answer, what with its disappearance in daylight.
3. Note that there is a new '105' (205?) model with a hard-plastic grip for you who worry about rubber grabbiness on a draw--but an appropriate pocket holster will deal with the grabbiness problem anyway, as well as help with printing and cleanliness issues, and even help with moisture / care issues. (Mika holsters)
3. I am using the CT has a dry-fire aid to develop DA skills with my DAO J-frames I bought specifically for carry and practice / alternate carry.
The 340 (.357 lightweight) has both a tritium front sight (good for aiming, night or day) and the LG-405 (boot grip) CT.
I turned in the 340 to my gunsmith yesterday for its action job, and picked up the 640. Based on my 340 experience, I've decided to add the LG-405 to the 640 (bigger grip for actually shooting .357s, not just .38 specials), and to have the standard black P&R ramp front sight changed out to a Meprolight as well.
You can't rely exclusively on them, obviously--but for a combat gun for civilians, I think they are the way to fly.
Jim