What level are you with your music? I mean to say, are you better off spending $399, or nearly double that amount, for your controller of choice? That's the first place to start.
I own both controllers. Here is the basic rationale:
1. Push 2 is superior to Maschine Jam for Ableton - and only Ableton
2. Maschine Jam can control Ableton, with 96% of the functionality as Push 2, albeit with no screens and less-awesome pads.
3. Jam can also be quite powerful with Traktor, for $19.
Push 2 has amazing screens, awesome touch-sensitive pads, solid knobs. Jam has none of those things, but a very smart implementation of the touch strips, which does make up for the lack of 8 knobs (technically speaking).
They are both amazing. I really enjoy the Push, but I find that I use it less and less these days. Lately NI updated Machine and Traktor with Link capability, so they can both sync with Ableton. They also expanded the remix decks to include "step sequencer decks" which are simple right now, but I think in short time will be more advanced. To a fairly basic/new producer, simply having remix decks you can bounce Maschine clips into, and then play with in Traktor, is plenty to start!
Yes, I am an NI-fan. I am also an Ableton fan. I usually start in Maschine + Traktor and eventually end in Ableton. Maschine still has some serious limitations, but they are working them out. That is besides the point.
For a few less dollars, you lose the better pads, screens. You don't really lose much control over Ableton Live, because the mapping is really nice with Jam already. Jam can control racks, synth parameters, etc. It's a toss-up. I own both! That said, with the recent Ableton mappings, I decided to spend a few hours in Ableton without the Push, just to see if Jam gave me any headaches. It did not.
I worked around missing the touch-sensitive pads by purchasing a used Machine MK2 controller on eBay for $250. Yes, I am advocating for two controllers vs. one to get the job done and I realize how that sounds. But, at closer glance: owning both controllers gives you the screens, 8 knobs, and BIGGER touch-sensitive pads, similar to the benefits Push offers. It also gets you a fully portable-standalone Maschine controller for sketching beats or triggering cues in traktor. You then have Jam alongside, for your more "session view" days, or to use with ableton... They also work amazingly side-by-side in Maschine.
Lately, Push 2 stays home. The Jam is in my bag every day. These are the basic reasons:
1. Push 2 is larger, thus it does not fit in as many packs
2. Push 2 requires external power to really light up. I hate plugging my controllers into the wall when I'm trying to be portable
3. Push 2 cannot control Machine like Machine Jam can control Ableton, so I get 2-for-1 functionality with Jam
4. When I "need" touch-sensitive pads, I pack MK2 along.
I can sandwich MK2 and Jam in my MONO backpack and roll out, but the Push 2 will not fit in the backpack by itself!
If you decide to go Push 2, mine is for sale as of this week. It'll be on eBay in the next few days.
Would I love to have both? Sure. Do I "need" both? No way. In fact, having multiple things to master = distraction. It's enough to have Ableton, Machine, Traktor and the massive libraries/plugins to learn... Let alone multiple workflows for the same program, based on different control units.
I hope my meanderings helped.