It depends upon case to case. If you can take the input credit and get it adjusted with your output liability then there is no problem in not availing the SSI exemption. By not taking the SSI exemption ultimately your cost will get reduced because you can take the service tax paid as credit another wise it will become your cost.
I do have replied for the same. The small scale service provider exemption provides you the exemption from payment of service tax upto the value of Rs. 10lakh. But by taking so you wont be allowed to take the credit of service tax paid by you and ultimately it will become the part of your cost, due to which the value of your service will be higher.
It is option for the assessee to avail this Rs. 10 lakh exemption or not. It is open for the assessee either he wants to avail the exemption or not and if he do not avails this exemption then he can take the credit of the service tax paid.