What I will tell you about kettles is that you do not need to use the smokenator to be able to smoke on the kettle. There are different methods to get longer smoke times without having to add more coals. Search the ring of fire method. I have gotten 8hours at 250 this way and have done a couple briskets this way.
Now don't get me wrong. I love my Performer more than I like my OTGs. The convenience of the table is great. I'm happy that I have the ash catchers also isntead of the ash tray that the OTS's have. Also the hinged grates when needing to add more coals or some wood to coals when grilling.
The Akorn grill is a different cooker than a kettle. It can do low and slow and high temp searing. It is more efficient than kettles on fuel and hold temperatures a lot easier.
If i had your choice, I would go with the Akorn as it adds more versatility to your cookers where a performer you are getting 2 of the same cookers.
*Weber Mini WSM* *Weber Touch and Go Performer X3* *Sublime Smoke UDS* *Maverick ET-732 * World's Fastest Blue Thermapen **Pitmaster IQ110*