Buy CECHA01 or not for Cobra dongle?

Currently have slim model bought new about a year ago out of box with 3.50 FW. Upgraded to 750g WD black internal with 2tb external. Currently running REBUG"s most recent firmware with XXMB+ freakin sweet. Soon to be proud owner of Cobra dongle looking for best compatibility for ps1 and ps2 .iso images. So the question is for the best retro compatibility with the Cobra do i need the emotion engine first gen console or will the PS2 loader iso do the same thing with my current slim model? Saw network loading of .iso images as an option with latest cobra FW, how well does this work ? Would rather add hdd space to server for shares than external drives to the collection on the media cabinet.

BTW big thanks to XXMB+ creator and dev for youtube support on 3.55 without a keypad.

You need the EE for compatibility. The PS2 emulator on the slim and later phats is week--it only has good emulation on a few titles. Personally, I just use my Phat PS2 with a 500gb and HD loader and Free Mcboot or PCSX2 for PS2 titles. It's not worth the extra expense and hassle to get a CECHA01, and they aren't so reliable anymore considering they are usually 6 years old.