Sony A7III (24MP, $2000)... 1.43 lb./650 grams
Canon 6D Mark II (26MP, $1300)... 1.51 lb./685 grams

Sony FE 24-105mm f/4 OSS ($1300)... 1.46 lb./663 grams
Canon EF 24-105mm f/4 IS USM II ($1100)... 1.75 lb./795 grams

1318 gram Sony combo versus 1460 gram Canon combo.... a savings of 142 grams... or 5 oz.

But the original poster isn't using a full frame camera now, so needs to compare the size/weight of the above with what they have now and other APS-C cameras and crop sensor lenses...

Canon 70D (20MP)... 1.66 lb./753 grams
Canon 80D (24MP)... 1.61 lb./730 grams
Canon Rebel SL2 (24MP)... 0.9 lb./406 grams
Canon EF-S 18-135mm IS STM... 1.06 lb./480 grams
Canon EF-S 18-135mm IS USM... 1.13 lb/515 grams
Canon EF-S 15-85mm IS USM... 1.27 lb./575 grams

Sony a6500 (24MP).... 1 lb./453 grams
Sony E 16-70mm f/4 OSS... 0.68 lb./308 grams
Sony E 18-105mm f/4 OSS... 0.94 lb./427 grams
Sony E 18-135mm...... 0.72 lb./326 grams

Assuming they are using one of the above EF-S lenses on their Canon APS-C DSLR, in all cases a full frame Sony MILC and lens would end up heavier ...

When I bought my A7r2 I had no idea how useful IBIS actually is. Buying a cheap tripod in lieu of stabilization could only be suggested by someone who has never used it. A tripod is an extra piece of gear that must be carried and set up, inhibits free movement and positioning and is generally a pain in the butt.

Of course a tripod has its place and is not only useful but invaluable in many situations, but I am finding that IBIS has been a godsend, allowing me to get a multitude of shots that would not have been possible (due to lighting conditions and the need for speed) and at lower ISOs that I could never have done without it.

When I bought my A7r2 I had no idea how useful IBIS actually is. Buying a cheap tripod in lieu of stabilization could only be suggested by someone who has never used it. A tripod is an extra piece of gear that must be carried and set up, inhibits free movement and positioning and is generally a pain in the butt.

Of course a tripod has its place and is not only useful but invaluable in many situations, but I am finding that IBIS has been a godsend, allowing me to get a multitude of shots that would not have been possible (due to lighting conditions and the need for speed) and at lower ISOs that I could never have done without it.

I moved from Nikon to Canon at the beginning of digital as I felt that the Canon chip at the time provided better color. 10d, then 40d, then 70d and added a 2nd body SL2. The latter was because of weight. I've noted before I had a bout with cancer, 4 major surgeries later (missing esophagus, parts of small and large intestine), I'm still around but I have occasionally a tremor which screws up my shot. I believe I need the 5 axis stabilization which most Canon products lack (all but the M5 which is video only). Sony color seems about the closest to Canon and I've been debating getting a full frame. I'm leaning towards the A7iii or A7Riii. I primarily shoot landscape and birds. I have several Sigma lenses and I understand with the MC11 adapter they work well. For the Sony I will probably get the 24-105 f4 to start. Have any of you made the switch and how has it gone to date? Thank you for your help.