Thats not true. I thought the same thing very recently. Some member on this forum said i was wrong. I went and checked / research. He was right.An X-Sight is fine, but they are also very, very heavy.
For decades it has been the common thought that larger objective lenses "gather" more light. The reality is that it's not exactly true. What does make a big difference is the diameter of the scope tube with regard to the amount of light that passes through the scope. All else being equal, a 30mm tube will transmit more light through the scope than a 1" tube, and a 34mm will out perform a 30mm.
IMO, a quality LPVO with a 34mm tube is the best option w/o making sacrifices for weight and clarity. Primary Arms offers models that will do the job and not break the bank.