My take on the XL50 for what it's worth (not much) is mixed. I had one for about a week before the switch died (got stuck in the ON mode), after that I returned it and never got another one.....not because of the switch failure (nobody has perfect QC, though Mag is generally very good in this respect), but more because I didn't feel a connection when the holding the XL50 that reminded me of shaking hands with an old or new friend (or whatever) like I have with most of the Mags that I have owned.
I like that the XL50 electronic switch, clean throwy beam and easy access to high and low mode (could do without the strobe), but there a few things I don't like. One is the 3 AAA/battery carrier set up, I have never liked these and would much prefer a 1 AA light, which would eliminate the need for a battery carrier (which is apparently a point of potential failure reported in many of the long term reviews on amazon) and would allow for a slimmer form; heck I would even take a single C cell configuration keeping closer to the original 3AAA form factor (would probably need to be a little fatter to accommodate a C cell). For the short time I had the XL50, I missed the lack of a momentary mode and it seemed that it ate up AAA cells fairly quickly. I also didn't much care for the round cylinder shape of the XL50, I found it kind of slippery and sometimes I grabbed it and tried to turn it on by pressing on the wrong end. I also missed it not having a clip, although I now see that the XL50 is often sold with a Mag Tac clip which should solve this problem as well as improving the grip and providing for the attachment of a lanyard. The construction of the XL50 also struck me as being not quite as solid as most other Mags including the similar Mag Tac and the Mini Mags; in fact the XL50 kind of reminds me of a pumped up Solitaire more than anything.
After returning my faulty XL50, I thought I would get a XL200 which has a few more bells and whistles I would like to check out, but I somehow never did.....now that the new warm white XL50s are coming out, might be a good excuse to get another XL50.