To tank or not to tank, it should not really be a question imo....
Having a compressor without a tank for reserve capacity will increase the amount of time you take to fill tires and also limit you by your compressors duty cycle.
If you think about it in an electronic analogy, it is like hooking your winch up to your alternator without a battery to provide stabilized capacity.
if you are constrained by budget that is one thing but I would strongly consider keeping a 2gallon reservoir on the long term list. You can always add one later. Beyond storing additional air to get jobs done quicker (average psi longer duration), they also allow for small bursts of greater cfm at higher pressure too that is handy with air tools or setting a bead on a tire. Granted, air tools are heavier and more expensive to carry and depending on compressor and reservoir size limited in operation times but for the additional $100 in parts for the reservoir it seems like a decent value proposition. Especially for gear intensive persons like myself. By the way....
Check out the atom air from Extreme Outback Products. It is small and has a 100% duty cycle. I am now installing two of these rather than one Vair or Extreme air jr. If you look at the stats for it, two atoms create the same max psi and cfm as the jr. but have 100% duty cycle, they are smaller physically, and redundant if one fails (you still have the other at 50% CFM in your system. Nice work George.,....:wings:
http://www.extremeoutback.com/index.cgi?cart_id=6293640.440&pid=115