Another light you might like is the Shiningbeam S-Mini II. This light is about as small as the Quarks, with similar versatility, but at a lower pricepoint (about US$42 plus shipping). The light takes 2x123 primary cells, or 1x18650 li-ion rechargeable, or 1x17670 li-ion. It features a three stage reverse clickie: L-M-H. Low is about 20 lumens (giving a really lonnnnnng runtime). Medium is about 200 lumens (about 4-5 hours continuous runtime). High is about 400 emitter lumens, yielding about 1.5 hours runtime. Also, both the S-Mini and its predecessor, the L-Mini, are sometimes available in the Marketplace at reduced cost. (The input voltage limit on the L-Mini model is 4.2 volts, so stay away from CR123 cells in that light.)
The beam pattern on my S-Mini is slighter tighter than on my Quarks, yielding a slightly longer throw. That noted, I hike mostly in woodland environments, where a floody beam pattern is useful. (When I hike in the Sierra Nevada range however, I prefer throw, lots of it.) The S-Mini is not programmable. By comparison,, the Quark lights have several hidden signalling modes, easily available with a few quick twists of the light head. If you plan on hiking in remote areas, at least one person in the hiking party should have a light capable of producing these attention-getting signals.
There is no shortage of choice among backpacking lights. Let us know what you ultimately purchase.
Finally, remember the community motto: When in doubt, get both!