https://www.candlepowerforums.com/posts/2824704&postcount=214You can mod the Sylvania with Cree, you'll get twice the output with the same run time.
current usage on high after upgrading to a P4 cree went from 350ma to 450 ma which is about 28% higher current so runtime would be reduced by a like amount. with a Q5 I got 440ma usage. I replaced the R5 resistor with a 70 ohm one dropping the current from stock 350/75, upgraded ~450/75 to 250/28ma (these are high/low settings). I compared a Q5 lantern at 250ma to a P4 at about 450 ma and the P4 is brighter but not by very much, in use they would be close to the same but runtimes I estimate as following:
stock 350ma/75ma alkaline 7/30
P4 450ma/75ma alkaline 5/30
Q5 250ma/28ma alkaline 10/100
these are estimates on nimh high output runtimes should increase slightly and low output runtimes decrease due to alkalines losing runtime at increasing current levels.