I bought two G15 lights and they are great. The quality feels premium and the light is bright and reaches far. I'm not a flashlight enthusiast and don't know much about the LED types and so on. All I know is that this thing does its job well.
I own two E70s and love them. They are the reason why I gave the G15 a go. If you like the E70, you will also be impressed with the G15.
They are quite low profile, similar to the regular Surefire Scout. A lot better than my Klarus for example.
What I did not like (reason for only four stars) are the accessories.
The M1914 (Picatinny) mount is good. Nothing breathtaking but it gets the job done.
The MLOK mount variant was not available at the time of ordering but the light is compatible with standard light mounts from Magpul, Arisaka or any cheaper versions from AliExpress.
The remote switch is okay. Cable length is adequate but there is a short delay when activating the switch. It's not a big deal to me but it is noticable and other lights I have are "faster".
The rail mounted holder for the remote switch is not great. The switch is too thick where the cable is attached and it won't fit in the holder without effort. Maybe it's supposed to be like that but I have seen better implementations.
The MLOK switch holder is useless. It does not come with screws or T-lugs. So there is no way you can attach it without getting extra parts. All my potential donor MLOK gear uses button head cap screws (rounded at the top). What you need are flat head counter-sunk screws. Button heads stand off too far and make it impossible to attach the remote switch to the holder.

So would I recommend the G15? Yes! The light is great!
They should think about fixing the remote switch delay and add screws and T-lugs for the MLOK mount. Just get a good product and add it to the accessory section. I'm happy to pay extra for it if it does what it says.
Will probably buy more of the G15s in the future!