Here's some info I ripped from another forum.
Chorus: the multi-delay chorus on the Mobius appears to create a lush chorus that I can't replicate on either my Modfactor or Pitchfactor. If anyone has any recommendations on delay and pitch settings to create a lush, deep chorus they'd be much appreciated. Apparently the multi-delay chorus on the Mobius uses three LFOs. Others have said they get close to a polychorus sound on the Modfactor using the S-mod and D-mod knobs to simulate multiple LFOs. Otherwise, the other chorus and vibrato modes appear to be very similar. I love being able to use the Pitchfactor to control delay and pitch though - you can create some very interesting and unusual chorus sounds using H949 in particular.
Flanger: The flanger sounds very similar: Modfactor lacks the negative through-zero setting (which I don't miss), but apparently this can be acquired using a mono set-up. Modfactor has the 'Jet' setting which is a really intense negative flange that totally takes over your sound. I don't think I've heard anything similar on the Mobius. In the demo, the Mobius produces a nice metallic, almost percussive flange on slow settings which wasn't easy to replicate on the Modfactor. I actually reproduced this sound quite easily using the Lo-Fi mode on my Timeline.
Phaser: Not compared the phasers much. They appear very similar. Modfactor has more settings, including Negative, Positive, Bi-Phase and through-negative - so there's possibly more sounds in the Modfactor, especially if you add S-Mod and D-Mod to the equation. Modfactor lacks the stereo spread setting for phaser which would be nice. I like the presence of 'headroom' on the Phaser and 'drive' on the Rotary in the Mobius to create different flavours and to dirty up the sound.
Rotary: To my ears the Mobius rotary does sound better. I don't use the rotary much on Modfactor though so I might not be setting it appropriately. Mobius seems to have a really nice stereo depth that I can't replicate on my Modfactor. Others may be better placed to comment on this one.
Vibe: can't comment. No vibe setting on the Modfactor.
Filter and Formant: really no difference. Use of D-Mod and S-Mod knobs here though on Modfactor allow for some crazy time-synchronized filter effects that the Mobius can't get near.
Tremolo: user-defined tremolo patterns in a pedal is genius!!! I hope Eventide can implement this somewhere in an update. The closest I can get to this is on the Harpeggiator. It doesn't allow you to programme trem patterns but it does mix pitch and other effects to create some amazing, unique rhythmic patterns. Again, use of D-Mod and S-mod on the Modfactor also creates some interesting trem patterns as well.
Autoswell: this sounds great. I REALLY hope Strymon update the Timeline autoswell with this algorithm. I don't find the Timeline autoswell usable at all. The settings available on the Mobius suggest that users don't have to mute their strings before the volume drop kicks in again. I can create volume swells using the envelope setting on Tremolo in Modfactor but it requires the strings to be muted each time (similar to Timeline). Closest I can get to the Mobius autoswell is using the Attack feature on my Hog.
Destroyer: this is unique to Strymon. Sounds amazing. I seem to able to replicate all of these sounds on the Timeline though with the delay dialed down to 2ms and the mix to 100%.
Quadrature: I can create very similar sounds using the D-Mod and S-Mod knobs on the ring modulator and the tremolo settings. In fact, the Modfactor might offer more control as you can select the actual frequency of the carrier wave and apply both Amplitude Modulation and Frequency Modulation at the same time. Very different sounds can be produced using the AC and DC settings on the Modfactor as well.
Layout and controls: I think modfactor wins here. I bought the Modfactor as a modelling pedal and I love the fact that I can control waveshape and modulate that waveshape using all of the knobs in front of me - no sub-menus required. Each modulation can also be controlled by an envelope setting so the modulation responds to the input signal. There was a steep learning curve with the Modfactor, mainly because the lack of information in the literature and videos. I've learnt a lot in the past week by watching the strymon videos and then trying to replicating the sounds in the Modfactor.
Key Differences: user-defined trem in Mobius, Vibe machine in Mobius, Autoswell in Mobius, Undulator in Modfactor (amazing synthy sound created using detuned delay lines and FM modulated tremolo), Modfactor offers full control over waveshape and modulation of that waveshape in every mode (so you can apply frequency modulation to a phaser, flanger etc.), Modfactor offers envelope setting in every mode.
Conclusion: overall I'm very happy with my Modfactor. I won't be swapping it for a Mobius like many seem to be doing, mainly because of the S-Mod and D-Mod settings and the Undulator. The difference in the other modulations appears to be quite minimal. I would like Eventide to try and implement user-defined tremolo patterns though and Strymon to update their autoswell algorithm in the Timeline.