Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: How will this superzoom lens perform on a high megapixel sensor?
Document: No lens changes means my camera sensor stays clean and I don't miss any pictures because of being in the middle of a lens change.
This is one of those items that gets used to death.. It is not perfect, but close.. This lens stays on my camera all the time.. Only when I clean the camera sensor does this lens come off.. Well there might be few more times, but it does the job of many lenses, so I do not have to take it off.. It does everything for me...
I love this lens and leave it on my camera all the time. Once in a great while, I wish I had a little more wide-angle, but I've used Photoshop to stitch a couple of images together to go wide.One benefit from keeping a single lens on your camera is that you don't get dust on your sensor.
First, unless I am out on a "macro safari" I don't generally have the 105 mounted, so it isn't always "at the ready" for targets of opportunity. Second, with the 18-200 racked out to 200mm, it focuses about 8 inches from the front of the lens (which equates to just over 19 inches from the sensor), which provides a pretty decent close-in range.
If there were any single problem with the 18-200mm lens it's lens creep. If you haven't experienced lens creep previously this is something you really need to be prepared for because it can become quite frustrating at times.For the amateur photographer or weekend warrior this one lens will save you from swapping lenses which will in turn save you from the expense of having your sensor cleaned every few months.
I also use this lens the majority of the time for everything from close ups, portraits to landscapes. You can get as close as a foot with great shallowness yet decent depth of field for landscapes and similar shots. With the D300s sensor you actually get something like 35mm to 300mm. I hardly need anything wider but the extra zoom makes this lens all the better.
There's no reason for you to miss shots that the guy next to you with his little Panasonic superzoom is going to reach out and get...a very slightly less sharp picture still may be worth a thousand words!
This lens is the only lens you will ever need. I am sensitive to the possibility of getting dust on the sensor so I really like this lens - I never take it off of the camera. Wide angle to telephoto it serves my every need - from portrait to landscape, products to wildlife. It is not the fastest, widest or longest, but it easily handles 95% of basic needs and the convenience, flexibility and cost of this lens more than compensates for the 5% I choose to miss.
High quality product all in one lens for the average photog. All I thought it would be and much, much more.
Don't buy it if you are short on budget (get your kit lens and one 35mm or 50 mm prime for less price). Telephoto capability in this lens is almost useless because of noise (low light and high iso) -- get a prime lens if you are doing wild life or telephoto related photography.
Answer: Stay with the 200. Vignette is minimal to none and the clarity of the 18-200 is very impressive. Clear and sharp edge to edge(this impressed me the most.) You wont miss the 300 and you can take the money savings and apply to another lens.