Selfbuilt provided an excellent summary of this class of lights! Thank you!
Am between trips, so I have some time to comment about these 4xAA lights:
The SRA40 has impressive output regulation! very bright, a long throw. unfortunately it is too large/long/bulky. gone.
The E41 was good, although the "Illumination" upgrade version was a good bump-up in brightness - well worth the price difference. I never had a switch covering problem with the E41 although I could see some slight ballooning when hot (Eneloops do outgas!). The EA41 is still better than the E41, with good switches & coverings. I still have 2 EA41s. all of the CW or NW E41s are gone.
Eagletac GS25A3 is small, but the brightness from 3xAA cells results in noticeably shorter run-time than the 4xAA lights. One of the pins failed on my single copy - returned for refund. Those pins are simply too small! The MX and SX versions with 18650s are more durable.
The D40A is a very nice light, bright, good regulation, but a bit too long in length. the switches are also a bit questionable, either regarding finding the correct switch with freezing fingers (or gloves), or the plastic covering is unacceptably variable in pressure between copies. some switches had a good 'click', others were mushy. The lanyard position on the side was odd. All 3 of my D40A copies are gone.
The F40A is a good successor to the D40A. Much smaller and more compact. A keeper so far. Be careful with the Red/Blue/& white strobe which will attract attention, maybe not the kind of attention you want. Some LEO may have had a bad day and then he sees your strobe. The F40A multi-color LEDs might be OK for EMS/SAR personnel, especially in rural areas.
The TN4A was bright, but the battery slots would not accept a standard Eneloop w/o jamming them in and then prying them out. The beam on turbo was nice, but the yellow/green on any lower level was worse than regrettable. Returned for refund.
Brightness between these 4xAA lights is difficult to compare without a integrating sphere, or simply a white ceiling and some adroit covering/uncovering of the beams on high. but if the beam color is very different, the comparison becomes nearly impossible. The spot & spill size varies rather widely between the lights. Very subjective as to which is better.
I am transitioning back to 4xAA lights from the single-cell 18650 Li-Ion versions, all of them in the 800-1000 lumen range. Why? There are very few non-flashaholics that I can trust with charging a Li-Ion cell. The lights with integral charging are a good idea, but the Li-Ion cell is still non-standard. I dropped all RCR123/CR123 lights long ago - run time on a high output was simply too low for me. Not sure what I will think once I move back to Germany, except that very high-output lights are nearly unusable anywhere near population centers. Someone will call the Polizei! Eneloops are readily available in Germany at the Mediamarkt outlets.