I actually went out to get a pair of the Summit bins for my non birding spouse. However, we both thought that they were obviously out performed by Pentax 8x21 UCF M (at a similar price). This didn't entirely surprise me since the latter are mini porros. At this end of the market porros always represent a better bet optically. They are a little more bulky, but this suited my wife who, like me, finds small roofs much too fiddly to use,
John