You have gotten me thinking, maybe I just need to pony up and get a high end model. Given the rave reviews and obvious low light performance, a good value appears to be the discontinued zeiss fl 8x42 series. The ht's are intriguing too. Maybe a way to get lighter binocs with similar light gathering as the el 10x50s
A bin with a larger exit pupil will most likely be more comfortable in low light.
How large EP you need depends on your pupils ability to dilate and the light levels you will be using the bins in.
Personally I prefer 6mm+ EP in low light and my 7x42 FL is the most used when the light is low.
Due to the weight a 50mm bin will never be on my list for walking around usage and 10x is not stable enough in my hands + the FOV is too small.
For more stationary/tripod use in low light a 10x54/56 would of course be more useful.
Bins I would check out are:
Zeiss 7x42 FL (AK prism, 93% transmission)
Leica 7x42 UV HD Plus. (HT-glass, SP prisms, the 10x50 have 92% transmission according to some info)
Zeiss 8x42 FL (AK prism, 92% transmission)
Zeiss 8x42 HT (HT-glass, AK-prisms, 95% transmission)
The FL:s can be found used for a reasonable price.
If you really need 10x mag I recommend stepping up to at least 50mm.