Switching to Nikon18-300 mm VR?

Hello!

I am considering switching to the Nikon 18-300 MM VR from my current lenses .and I would request some advice/suggestions regarding that. But first a few facts about myself and my equipment:

1. I am an amateur photographer-learning new things about digital photography every day and extremely keen to continue on that path!

2. I enjoy photographing wildlife, birds and landscape the most (I don't enlarge and/or print so much)

3. I use a Nikon D5100

4. I currently use a Nikkor 18-300 VR (the kit lens) and a Nikkor 70-300 VR (that I am quite happy with)

Now, I am thinking of exchanging the two lenses I currently have, for the Nikon 18-300 MM VR. I am quite tempted by the convenience of carrying one lens (especially considering the shots I missed in Serengeti while changing lenses!!) but I ofcourse don't want to compromise on image quality.

Is it advisable to make this switch?

Your suggestions/comments/information will be highly appreciated.

Thanks

BaanC