stringbuilder manipulation performance

can anyone tell me the performance difference between:
stringbuilder.append
stringbuilder.appendformat
stringbuilder.replace

As a general rule, StringBuilder has great performance over concatination using simple strings concatinations, specially when the data to be concatinated is unkown.

Regards

using the string builder itself has a big impact in string munipulation !!! each method menthioned above has a difference in the behaviour and can do different job as required but if you are aware of the performance what to use and which one .....i will not be really bothered as the stringbuilder methodology is great in terms of performance so you can choose what will do the job for you !!!

HTH