<scratches head> well that depends on your budget - are you a church mouse operation (like yours truly) or have other people's money to spend?
Both of yours #3050 and #3600 have OpenGL, so foremost should be getting a non-OGL one - a 27xx (e.g. Roku1) or 5xxx (RokuTV) model. Minor graphics (in)abilities may surprise you.
Next would be a 4xxx player.
See this https://forums.roku.com/viewtopic.php?f ... 15#p536994
for overview of player models in use.
Meanwhile, new evolutionary models 37xx, 46xx are coming in September - cue http://zatznotfunny.com/2016-08/roku-pr ... -plus-hdr/