there are differences between the 2 units regarding arpeggios. Eclipse uses delays whereas Pitch Factor HarPeggiator creates dual 16-step arpeggios that combine three elements: 
1) dual 16-step pitch-shift sequencer
2) dual 16-step rhythm sequencer
3) dual 16-step effect sequencer

You may want to check its user manual for more details.

They are very different.

best

I