Lantern32,
With truly all due respect, there are a couple of reasons why your post is somewhat problematic. There are numerous pre-existing threads concerning these lights in which much of this has been discussed. Also, your question is extremely broad. Which Surefire models, for example? There have been many, and they have varied widely. Which Malkoff drop-ins? Finally, previous discussions about the relative merits of these lights tends to engender partisan sensibilities and strong emotions. For example, one person will say, "Brand X is a fantastic light!", while a respondent will say, "Yeah, I guess, but it's way overpriced - a ripoff - and there are much brighter lights out there!" Because these threads can get quite heated, they frequently get shut down by the moderators. You might first want to do some research on these brands on this forum, and then possibly re-post with somewhat more specific questions about specific products. Just a thought. I truly do not wish to come across as patronizing. Very generally speaking, the brands that you have mentioned are highly regarded by some, but there will be those that possibly disagree.