RS125 connect to MFD via 0183 or SeaTalk?

I currently have installed:

E80 Classic
125 GPS
S3G SmartPilot
SmartController
ST60 Speed, Depth, Wind
ST6001+
E55059 MUX
ICOM m422 VHF with DSC
FloScan 9500 with GPS interface

My configuration currently has the RS125 connected via the MUX using 0183. Questions:

1. Is there a preferred method for connecting the RS125 to the E80, provided either way will work?
2. Are there any benefits in connecting one way or the other?
3. Are there any features or speed lost connecting one way or the other?

Thanks!