Question: Low light performance comparison between the SX40HS and the SX50HS

I think that the difference is more conversational than practical.

At wide angle maximum, SX40 has f/2.8 and SX50 f/3.4, but how often does one use f/2.8 in this focal distance?

At 40mm., SX40 has f/4.5 x SX50 has f/3.4.

At 200mm, SX40 has f/5, SX50 F/5.6.

At 525mm. SX40 has f/5.8 up to 840mm, versus SX50 f/5.6 way up to 950mm

A tie, I would say...