I'm contemplating adding a full frame L-body to my stable. Everything I've read about the S5 sounds like it's an absolutely fantastic camera. My only issue is the size. My day-to-day carrying back is a Peak Design 6L sling. I think it might be hard to fit the S5 in there with a lens.
Has anyone purchased an S5 and later regretted it due to the size and weight?
I have size and weight limitations due to some health issues, and I have small hands also.
The S5 is definitely on the high side of my comfort zone. However, after a very short adjustment period, I have no problems at all with it with everything up to and including the 70-300mm lens
The only issues I have are with the Sigma 150-600mm, which I do require monopod or tripod support to use (of course, that's about a 4 1/2 lb lens, so not a surprise there).
I also use different bags than I used for M43, as the lenses are enough bigger that they need more room. (I have a separate bag for the lenses I am not using at any given time, and the 150-600 has its own bag, as you would expect.)
Additionally, I use a sling type strap, vs a wrist strap, for regular carrying. (For my M43, I use a wrist strap except for the PL100-400, when I use the sling strap also.) I find the sling strap with the S5 keeps my wrists from getting fatigued, which is the only weight issue I had with the S5 when I initially was using it with a wrist strap only.
So, in summary: Expect to modify your bag and strap lineup, and you should do great. If you do decide to shoot long tele, though, be prepared to use more support, but for everything else the adjustment should be pretty smooth.
-J