Discussion about the Korg PolySix synthesizer

I've been repairing PolySixes for a while, and have had a number of
requests for MIDI interfaces.  I currently have access to two:  the
Bojan, which is a simple MIDI In device (with channel select);  and
the Miditek, which provides MIDI In, Out & Thru in Poly or Omni mode,
channels 1 - 16.  The only drawback to the Miditek unit is that it
disables the onboard arpeggiator (I'm guessing the designer thought
that the added access to MIDI arpeggiators & sequencers offset this loss).

It looks like I could provide the Bojan for about $60, installed;  and
the Miditek would go for approximately $140, installed.
My question to you, the users of the PolySix:  
which of these would you find more usefull?  -- and, do you think
these prices are reasonable?

Thanks.

~GMM