Which "Old" ones? The old gen1 when they didn't even have a momentary? Or gen2, which has the same general form and function as the current models, and was blue-ish, but generally white?
The way I read the reviews, the third generation appears to be nearly three times the brightness of the first/second versions. The trade-off was in run time.
Find a light you are familiar with in the chart and compare the relative brightness values. The site says you can estimate lumen value by multiplying the chart value by 1.39. Unfortunately there is no chart number for the gen 1/2.
I'm glad I stumbled across this thread because I have an X5 that I bought several years ago, way before I ever knew that CPF existed. Now that I've added quite a few "real" performers to my collection, the old X5 pales in comparison in brightness, but especially in color (PURPLE!... sheesh).
Mine is obviously the 2nd generation, having a momentary plus twisty switch, and throwing a purple haze flood of about maybe 1.5 lumens (in my cynical estimation).
I'm not exactly thrilled with it, but I can't bring myself to throw it away because it's made so well.
Perhaps I'll convert it to 110v AC and make a little table lamp out of it or something...