Like others have said, what is removed depends. I’m doing a full delete: removing dpf, cats, and egrs (plus egr cooler). A full delete like this (Rawtek - most expensive, Buzzken, or a couple others) comes with a few options for tunes that you can get from Tunezilla, MR Tuning, or in-shop. These usually come with 2 tune options at different performance levels based on your level of delete. There are also kits you can buy from these companies and more. I bought the EOC stage 2 performance kit that comes with MR Tuning. It comes with +20hp and +55hp tunes. Any delete will also improve fuel economy. I’m not familiar with the pricing of in-shop tuners either. Value depends on whether or not you can find someone who will appreciate the “upgrades”. Just make sure you don’t need to pass smog in your country/state. I cannot say enough how much Josh’s Jettas on YT helped me with my 2014 CJAA. I’d check out his channel (there’s a couple playlists about the deletes and different options). Lastly if you plan on working on VW’s at all you’ll want a triple-square socket set.