Windows 8.1 Further Upgradability

Hey guys,
I'm currently using Windows Vista and I'm planning to upgrade to Windows 8.1 (purchase).
Since I'm purchasing, I'm wondering whether I should put money on Windows 8.1 or wait for the next big upgrade (Windows 9?). This concern is mainly due to the bugs present in Windows 8.1.

Also, can anyone tell me whether I'm able to upgrade to Windows 9 for free from Windows 8.1? If I'm able to, I will definitely get Windows 8.1 now. If not, I will wait for Windows 9.

Thanks for your time

The rumors are that Win 9 will be free to Win 8.1 update 1 users but nothing official yet

Win 9 will be next year some time so it will be a long wait.

All Operating Systems have bugs so my recommendation is to go ahead with 8.1, it really is a great OS.