Even We prefer and reccommand Aramex. They are safe, relaible and cost effective. Cant really put rates here but for an idea they are 1/3rd of what you normally pay for DTDC walkins. Have a credit period of about a month as well.
Plus a account handler is assigned who takes care of any problems realtime.
Cons as with anything are a few- in some places they have very poor service-
1- Goa
2- Some Parts of NE
3- Orissa
4- Andhra Pradesh
So if you are sending any parcel to above areas keep tracking it regularly.