One thing I haven't seen mentioned here is whether or not 37s will fit between your chain stays or fork. Cyclocross and touring frames usually don't have a problem with this, but many other frames do. You may want to double check that first.

Of my two main commuters, one has 32s (Schwalbe Marathon Supreme) and the other has 35s (Schwalbe Marathon Racer) and sometimes 37s (Schwalbe Marathon XR). I prefer the 32s on tarmac and 35s/37s for dirt roads, but the speed and ride quality is really close. The 35s/37s are slightly softer and slower, but not enough to make a big difference.