Nikon 55-200mm VR or Sigma 70-300mm APO DG

[rampokker]

Hi. At the moment I have a Sigma 70-300 mm DG lens attached to my Nikon D5000. I find that image quality is a bit of a problem when I'm at 300mm, I find that I loose crispness if I try to photograph distant objects, if I stabilize the camera its not bad, but you don't always have a tripod handy, so I was thinking of replacing it with a Nikon 55-200 VR.
Will the Nikon be good enough to sacrifice the 100mm focal length?
I know I should really get the Nikon 70-300 VR but my budget does not allow it at this moment, I can trade my Sigma in on the 200mm Nikon and only pay in a couple of dollars (rands in my case).

Thanks in advance for the advise.

[OsmosisStudios]

Honestly, just save up the money for what you know you need.

[Docs500]

If the IQ is only a problem when using handheld between 200 & 300 -- then why change?
If the IQ below 200 is fine - then you arent gaining anything by changing.