I am just guiding the guy people...

I know 11.0592 is the best for serial comm but sometimes if apps demands you need to use 12mHz crystal and still communicate

You need a slower crystal then use 3.6864Mhzperfecto for comm slower m/c

each cycle will give me exactly 1 uS timing instead of 1.085uS as in 11.0592Mhz

I know baud rate is independent of crystal

And I do agree crystal stability should be checked first before using it in any critical apps where timing may make lot of difference..