A lawyer asked us, "should I advise my client to testify?"
There are many reasons that a defendant in a criminal case cannot testify. I will answer the question assuming that none of those exceptions apply and that your client could testify.
I prefer not to have my clients testify. The two main reasons are that the prosecutor has the burden of proof. Don't help them out. Don;t add stuff to their case. Next, I don't like to give the prosecutor the opportunity to cross examine my client. If you have ever watched Law & Order, Jack McCoy always gets the defendant tripped up.
In some cases though, I think its very helpful to call your client. In any case where there is a civilian complainant and no police officers are involved, I really analyze whether to call the client.
If the case is a domestic violence or a sexual assault, with a lot of physical evidence, I call the client to testify.