You may want to check some similar thread in general discussion forum, and a thread about Tiger airway in Travel forum. There got a lot more CSer sharing their experiences there
It all depends on the airport and airline. Usually 'a lot' means more then 2 pieces. A back pack which follow the size restriction is fine. Another piece of something (like small lap top on a sleeve like case) is also fine. I use to carry a tripod (of about 50 cm folded length on board Jetstar, it is fine).
I brought my back pack with lens camera and a tripod tied to it. I have another sling bag with clothes --- didnt have any problem. As long as the dimension and weight is within their recomendation I think you shouldnt have any problem.