We have been using IFM lately. Since they changed their distribution model their prices are competitive with Automation Direct and they are pretty compact for the power they put out.
We use the Allen Bradley 1606 models pretty much exclusively. I've never seen a failure with them yet and you don't need extra DIN rail space for another module to achieve redundancy.
I've never heard of PULS but looking at the datasheets, it sure looks like they could be the OEM for the AB units.
The reason I like Phoenix Contact "Quint" is because of its "Power Boost" capability. "Power Boost" allows temporary high current surges without dropping voltage, which is nice for handling instrumentation that has a start-up surge.
I believe there is a PULS model that does this also.
This is why they are a little more expensive.