I believe it depend more about what your are used to in your set up and what your expectations are more than just acquiring cool gear.
If you are really into the analog sound quality of the volcas and you have made this really work then the Beat Step Pro is the most logical upgrade to your setup. If you have all of the volcas then the Pro would solve a lot of headaches. Getting the E2 could introduce new ones.
If you are used to how the ESX or EMX work then I would urge you to look up Sauces videos on the E2. He does great comparison videos on the ES2 vs ESX.
If discovering that the E2 is not anything like an EMX or ESX is not an issue for you or you've never owned an ESX or EMX then watch Tarekiths video reviews on the E2. These are so well done!
It's important to really do your home work. There is enough resources here and on youtube to tell you if the E2 is right for you.
Try before you buy. Is there a music store that has demo one? Go there, mess with it!
If you do buy the E2, buy it from a place like Sweetwater or MusicansFriend. You can send it back if it is not right for you.
My personal experience with the E2 is simple. When I saw that there was a Kaoss pad and trigger pads, I was all in. The E2 with it's 16 parts/tracks easily playable with the track pad and triggers was going to solve a huge headache for me; too much gear at live shows!
I came from the Kaossilator and Kaoss pad world. I was using 4 different types of Kaoss gear in my set up plus 2 ES1's, a Volca keys and a micro Sampler. That's 8 pieces of gear I replaced with one box! I am very happy. I got the Sampler (I needed a sampler) and now everything I could ever want, in a studio or live, fits in one case.
I knew what I was getting into; a Kaossiltor Pro on steroids. This is exactly what I wanted!
Know your needs. Happy shopping
