Here's my personal experience, most recently while tracking express 103e.
Sharp lnb gave performance than airtel lnb. :k
While sharp was able to lock signals, and gave better quality.
Airtel lnb, didnt lock d signals even properly, signals were coming and going.
But, on d other hand, if airtel lnb locks d signals, then it gives better performance. The picture does not freeze even at very low signals.
Whereas in sharp, picture freezes in low signals.
Hence for out of coverage sats/ fringe signals use, sharp lnb.
But for non-freezing use airtel lnb.