I think OT is the best partner for it (and we’ll, usually the best partner for anything).
The things ST lacks, OT has in abundance:
p-lockable compressor
sample playback
deeper FX variety
dedicated MIDI tracks
Arp
more LFOs
song/arranger
parts/kits
The list goes on and on.
And with a combined 20 audio tracks, ST+OT is arguably the most capable Elektron pair.
And OTÆ shares the same color palette. 
I received it today and I have to say it is a cool machine - i tested it for a couple of hours but I feel I am much more creative on the AR mk2 and the Cycles for now
The 16 steps and the pads on both plus the plockable machines on the Cycles are a huge advantage if you are into rytm structures and new rytm structures
doesnt the ST have p-lockable machines?
Sound locks but not machine locks on the syntakt I think ?
From the manual
You can change a track’s sound to another sound (that uses the same voice type) from the Sound pool on any individual sequencer step
The manual defines voice types as either digital voice type, Analog voice type or Analog cymbal voice type.
C#@ts alive!
This thing is raw as fuck.
Five minutes playing with it and it’s ticking the boxes. It kicks hard like the Rytm, but there’s a bit more of a crispness to the sound, less muddy. Both the analogue and digital voices definitely sound better to my ears than they did on their respective forefathers, but that’s maybe just honeymoon ears. The master drive is really nice, opens up the possibility of some pretty heavy drum bus smashing whlie keeping my Analog Heat free for master bus duties.
This is not machine lock
I know.
But you can sound lock different machines on the same track, as long as they’re the same voice type, you just have to use the sound pool instead of the more simple machine locks on the M:C.
since syntakt is part of digi Trinity，the naming was a little confused，if takt = drum，this new one also a synth，why not call it SYNTRACK at first，little brother of OCTATRACK
THAT MAKE SENSE
I had my first play, it reminds me a bit of the pleasure of sex, but overall it’s better because you can’t make music with sex.
Sounds to me like you’re doing wrong.
I definitely make music during sex. It sounds something akin to Merzbow, but it still counts as music.
With that understanding, shouldn’t Syntakt be duodectrack according to you?
Takt is more like “rhythm” in Swedish, or “pace”. So “rytm” but even more Swedishfied + throwing “synth” in there. To me (as a Swedish person), the name makes sense as it is 
I wouldn’t see the Syntakt as the little brother of the Octatrack, they are very different from each other.
Exactly. It’s the non-sample sibling of the Digitakt.
you are right！octa and syntakt are total different thing
Fun fact, the Swedish word takt stems from the Latin word tactus, which is what the English word tact derives from.
Tact:
(music) The stroke in beating time.
Yes but i do not find it rad as it is rad and funky on the MC
I have played it just an hour this morning, so far not impressed, MC rocks
But totally ment for each other 
And Syn means gathering, doesn’t it ?
Well, syn is actually a Swedish word, it means eyesight. But that’s not what Elektron means in this context, they mean the word synt, Swedish for synth. 