You really need to include the performance shares in any market...

You really need to include the performance shares in any market cap calculation in my opinion.  Assuming they don't get issues means a smaller market cap and you own less of the company, however the milestones required to achieve the performance targets must be hit for the company to succeed and be successful + profitable.

If those shares are never issued, it means the company will have floundered and the current shares on offer will quite possibly be worth be less than what they are now.