I knew there were threads here about DSLR's and did a search but the ones I saw were about a year old. I figured enough had changed so I wanted some fresh opinions. In those threads, the only names I saw mentioned were Nikon and Canon and there were a few posters who had a D5100 and loved it so I figured I'd go that route. Don't want to get the minimum camera to do what I need but don't want to overkill either.
What kind of lenses should I be looking at that are better quality than the Nikkor 18-55mm and 55-300mm? I'm not opposed to spending more on better glass but don't want to spend double the money for a 5-10% gain either. Is Tamron a good quality lens? On the 18-270mm macro, am I giving something up by being able to get that much zoom with such a short bodied lens?
Tamron is a mid-range lens, its OK but not on the same level as Nikon. Some Nikon lenses are made in Taiwan, some are made in Japan. All of the Nikons are good, but the ones that are made in Japan are higher quality than the ones made in Taiwan. I think you can see the difference in the image quality between the different grades of lenses. Carl Zeiss makes great lenses for a lot of different camera makes.
General rule of thumb, for a given focal length, the lower the f number, the better the glass quality.