In the best of worlds I would consider buying 3 RTK units, but that is not being realistic at this time.
I currently own two Trimble 4600LS's and one Trimble 4000 SSE for OPUS work. My office software is Trimbles’ ancient DOS based "GPSurvey".
I would like to leave Trimble and possible move on to Magellan products one receiver at a time as the Trimble units fail.
Is it realistic to purchase one PM3 and the office software that goes with it and process the Trimble files in one form or another in GNSS Solutions?
Buying 1 PM3 plus software is not economical.
Buy 2 PM3s and the software is free. Plus, you can take direct advantage of the L1 RTK.
Additional money is required to get a software upgrade for L2. However, L2 capability is not neccessary to download a Magellan L2 receiver and submit to OPUS. For point to point project vectors L1 only software is adequate. But for that day when OPUS is down being able to solve it yourself from a distant CORS could justify the expense.
Paul in PA