Basically yes if you do not have time or skills to get your hands dirty and eventually all work might end up being wasted time :|

WARNING.
When flashing EMMC it means that all your PIM data will be lost so make backup and copy it to your desktop or to memory card on your n900 if you have bought one.

But before flashing I would advise to install conky (it shows some of top cpu usage processes running) or if you have basic skills on using x terminal then you might try running it and trying command:
top
Which shows what tasks are running. When you are idle there should be only little cpu usage byt xorg, but if there is some other processes using cpu constantly more than 2% then report here.