Considering that many human resources departments from most of the major companies don't know what's the difference between SCJP 1.2, 1.4, 5 and 6 (they only know they wanna recruit a Java certified programmer), do you think is worthy taking an upgrade to SCJP 6?
Wouldn't it be better getting another certification, like SCJD or SCJA instead?
Yes I agree with you on this one, if you are SCJP 5.0 certified then it is guaranteed that you are knowledgeable of the major features that the language provides up to date. Honestly there is no major changes between Java 5.0 and 6.0 therefore I would encourage you to take another certification so that you can broaden your knowledge and skills instead of upgrading to Java 6.0 which is not going to make any difference in your value as a programmer.
IMHO, if you are SCJP 1.4 or below, it is worth it to go for SCJP 6. There are so many new topics which are of immense use, that makes the certification worth it. If you are SCJP 5, then you don't need to go for upgrade as there is not much difference between the two...