I have both the ITP EOS A1, A2 SS, A3 upgrade and Quark MiNi AA, 123, CR2.
The ITP are slightly less expensive. They come in different colours. They come with a manual, keychain, 2 O-rings and a very handy clip. EOS models can't tail stand due to their attachment point for the keychain. They use the older XP-E emitters. Good solid keychain light. The A2 SS comes in a nice silver tin box with a window. The warranty is 30 days for defects in workmanship and 2 yrs for normal use and service.
The MiNi Quarks come in black or Titanium (more expensive). They come in a sleek fancier gift box which is nice. The grippier knurling makes it easier to handle (the titanium knurling have even more traction). The Quarks come with a 10 yr warranty and are reknowned for their customer service. MiNi Quarks are designed to tailstand. The also have their logo laser etched on the end (a nice touch). The MiNis are updated with the latest most efficient XP-G R5. They also have hidden strobe modes which aren't avail from the EOS series. When rechargable LiIon (not recommended by 4sevens)are used, the brightness is unbelievable. Accessories included are the manual, spare o-ring, battery (2 with the CR2 Al) and paracord lanyard (which I find very useful) but no clip.
For the extra few bucks I prefer getting the battery, latest brighter more efficent emitter, better knurling, more modes, and longer warranty with top notch customer service. The gift box is a nice touch. If the MiNis came with a pocket clip and options for different colours it would be a no brainer.
Overall both the EOS and Q MiNis would be a good choice but I see more value from 4Sevens. They're a great company that listens and develops what people want for a great price and I support them for that reason alone.