I knew it wouldn't be long until people were trying to make full Custom Firmwares since the creation of TN HEN.
Is a Custom Firmware really needed? I mean, the only thing you can do with CFW that you can't do with HEN is play ISO ROMs, but there are ISO loaders.
On the other hand, if it doesn't brick the living heck out of your PSP at first, it would be handy, because you would have more RAM, no crashes, and full plugin and homebrew support(which I'm sure TN can manage).
So, whether you get the CFW or keep the HEN is a matter of whether you want your PSP turned into a $100 - $200 paperweight or not(because you know it will if you install CFW).