I would probably go with the geared bike. It may be flat but headwinds might require a little drop in gear inches, and the stock top end with 1.5 tires is 88 gear inches or so. Keeping up with guys on 700 c bikes might be easier with higher gearing, if you wind up riding with other folks . Besides, should not take long to switch between fixed and geared. Switch chains and rear wheel and take off the shifter from the bars and off you go. If you leave the geared bike in storage and you want gears later it will be a lot more hassle than going the other way. Most of those who went fixed got a fixed or flipflop hub and had a wheel built up. You might be able to get a fixed cog on the Quando hub but I am not sure if that would require a wheel dish job or not.