the d300 was tested to 150k iifc (and that was tested to not died after) so only a third of the way through its life if you consider it was released mid (ish) 2007 and discontinued discontinued mid (ish) 2009 it has at best done 12.5k shots per year and at worst 25k shots per year either way there is still a lot of life left yet the rubber grip problems i dont think are limited to just the d300 as i have seen other nikon models affected also but it is not a huge expense to have repaired i have had mine since 2008 and have had no problems at all ....and yes would be a good step up from the d90 i think the difference in build quality is huge if nothing else