I have the Quark QT2L, which is essentially a different version of the same light. Throw with this light is excellent. Testing this light by shining it on a tree line across a couple of athletic fields from me, I can easily illuminate that treeline with the hotspot with the light on maximum brightness.
The XM-L2 emitter is large and be floodier than an XP-G2 emitter in any given sized head. Either go for a QT2A (non-X) or larger headed Turbo model - QB2A - which a I believe does (or would) hold the highest throw numbers in Selfbuilt's 2xAA, 1xAA, 1xCR123 classes, depending upon the battery tube you Lego.
As reppans mentioned the larger XM-L2 emitter will throw less than a XP-G2, assuming similar sized reflectors. If you had to choose between the two I'd go for the P100A2. If you are open to other options a Nitecore MT21A with the XP-E2 will out-throw both the Quark or the Eagletac.
Thanks for the info, i ended up going with the QT2A-X with the L2 emitter for the price. I found one for $50. I appreciate the information though about the types of emitters, i am building a collection and i am quite new to LED terms and specs.
The XPG will throw better than an XML, but not that much better. An XML is a lot brighter, so it makes up for some of the lack of throw just by sheer power. IMO, the XML is usually the better choice: much more lumens, and almost as much throw.