Should I save for the Nikon lens 55-300mm or buy the Sigma 70-300mm now?

Is it worth buying the Sigma 70-300mm now or saving for a bit longer to get the Nikon 55-300mm?

I don't want to hear people saying well what do you need it for and all that just tell me which is better. I know the Nikon is but is it much of a difference.

Just give me your opinion on what you would do in my position, Thank you!

I would save longer for the Nikon:

The Nikon has VR. I assume that the Sigma you are looking at is their bottom end lens that does not. VR will allow you to handhold the lens at 300mm and get sharp photos without a tripod. It really does make a huge difference.

The extra 15mm at the bottom end may not seem much but it does make the lens very versatile and will reduce the number of lens changes.

Top range Sigma lenses are as good as the OEM lenses and better in some cases. The bottom end Sigma lenses are OK but that is all. Image quality will be better from the Nikon.

Nikon KNOW how to make lenses compatible with their cameras. Sigma have to work it out by reverse engineering. Sometimes they don't quite get it right.