I haven't noticed the new 737-900ER seats reclining any more than ordinary, but then again I usually make an effort to secure 1B so my data points are limited when it comes to pax reclining into me.

I once had a 757 BF seat (old) that seemed to be broken and reclined several inches further than my seatmate's. Fortunately this was on a ANC-IAH redeye so I was able to get a pretty solid five hours of rest.