At most certain, I would recommend having a DEX console over CEX. Though if you a Rebug firmware you can constantly switch from CEX to DEX and vice versa only if you have your flash dumps with you. One of the common reasons for having a DEX console is the ability to RTM, though it is possible on CEX with CCAPI (also compatible on DEX) with the added power of target manager. But this depends on your preference, if you play CoD and wish to mod, DEX is most preferable since mods for CEX are limited (though this doesn't apply for every game). The problem I have had while on DEX is that getting online requires some extra stuff (hardly time consuming). Overall DEX is recommended and better than CEX on a bunch of points. To have my word, get Rebug since you can switch from CEX to DEX and vice versa from the Rebug toolbox at your will.
Well the ironic thing about all this affair is that, I still have a CEX machine xD