I just got my replacement s30r 2 in today and I have to say I'm somewhat disappointed with some things I didn't know they'd changed previously.
A few things: They did did away with the low voltage indicator, yet again, under the button and it's not just a soft rubber button.
The battery is inserted with the positive end towards the tailcap like in the picture. Also the positive terminal is, at best, flush if it isn't slightly countersunk so flat top batteries definitely won't work. I've tried some of my eageltac batteries with the notoriously short positive terminal and they won't activate the light at all.
The magnet in the new one is definitely a bit stronger than my s30R, it has no problem standing out horizontally where as my original one pretty much won't stick horizontally at all.
You most definitely cannot use old bases with the new light or old lights with the new base, which really is disappointing.
There are a few machining differences between the two. There is a lip, just above the new shorter tailcap, on the body of the new version and the hexagonal part that the switch is in near the head is slightly machined with different proportions of the smaller flats. And to confirm, the tailcap a are not interchangeable between them.
So in my opinion, if you want to use anything but the proprietary 18650 that comes in the light, the first gen is a better light. I emailed Olight today when I got my light and all my observations were confirmed. This one seemed opposite of my experiences tho. Referring to the switch and low voltage indicator: Yes, it was not a reliable feature and we decided to use a nicer material on the button and not include it.
I personally liked the flat switch with the light inside. The new switch has a slight protrusion again but it is nowhere near as bad as the old white switches the batons had.
sorry about the font change at the end. iPhone copy and paste changed it and I couldn't be bothered to try to figure out the default font and size.