This is a great point. You probably won't need support for something like a ProFace, but if you're doing robotics/CNC, camming, lots of coms, signal processing, or generally doing something platform specific, you need to have the training and support available, if not locally, then within a days travel. Of course, they need to have enough people available too.
Since this Forum is can make it seem that anything that isn't Siemens or Rockwell is "Off Brand" and poorly supported, I thought I'd list the top PLC makers in order from 2007 (This is just PLC, IO, and drives; some of these companies make much more money in other business sectors):
- Siemens (More than half of sales are in EU)
- Rockwell (More than half of sales are in USA)
- Mitsubishi Electric
- Schneider Electric (most sales in Electric Utility area)
- Omron (more than half of sales are in Japan)
- B&R (Privately held, rarely reveals sales figures publicly)
- GE & Fanuc (separate as of 2009)
- ABB
- Beckhoff
- All Others, such as ProFace, Culter Hamer, Honeywell, Bosch-Rexroth-Indramat, Baumuller, Kollmorgen, Koyo, etc. are less than 1% PLC sales each and account for about 10% all together.
All of the Brands in this list have world wide support available. Some, like Schneider have disparate product lines that are causing problems (they acquired Elau, and a lot of people left, the remaining guys are slammed). Some, like Beckhoff only sell direct and don't have many satellite offices (meaning you're paying for flight, rental, hotel for a support visit). Others, like Rockwell charge for even basic support.
This list order is from 2007, since then, Rockwell has grown more than Siemens (not sure if they actually overtook the lead), Beckhoff had legal trouble with Rockwell, but got in deep with cigarette machines to make up for it, B&R tripled in size and is now bigger than Omron, GE-Fanuc broke up, Omron gained against Mitsubishi, and Schneider started supplying everyone with re-branded Altivar VFDs and miffed the takeover of Elau. Keba has burst onto the scene in postal and ATM applications and is using that funding to try and go after Beckhoff/B&R/Schnieder-Elau (the high technology crowd).