From viewing alot of pics of peoples setups I have noticed quite a few people have there subwoofers set up front beside the mains. Being a big fan of dual subs this setup does indeed look good but after trying that setup myself I found that I am losing some bass in this configuration. Went back to locations on either side of couch listening area sounds alot better but doesnt look as good as front placement. The subs do make good coffee tables though
With dual subs opposite side walls or front/back walls often sound better than both up front because they help each other cancel out room modes giving you smoother sounding bass.
A lot of people put their single subs up front because it helps keep the sub from being localizable and often they just don’t have a better place to put it.