What do you think? Which one is better? Any advantages or disadvantages? Any users/owners?

I would think a trailer mounted model may be easier to move onto location. Long trailer is easy to move around, and the nice thing is when it is on location for an extended time (large projects) you could either bobtail the truck back to the yard, leaving the pump on-location, or if you have a sleeper unit just load it up with supplies and sleep on-location.

both units have advantages and disadvantages, but they all do the same thing. Pump Concrete. Im sure you would be happy with either unit

Pros:  Maneuverability, choice of power units.  Smaller engine powering pump and boom - lower fuel consumption.  Hours don't accumulate on power unit.  

Cons: Higher driver's license standard in some jurisdictions, longer set-up time.   Tractor pulling dead weight of trailer wheels, as opposed to driven on straight unit.

Regular Schwing VS Putzmeister issues....

Trailer unit is likely less cost to buy, even with included truck tractor.

For me its all about how much setup space they take in comparesment to the boom length.. If they both take just as much space to set up than the 55 meter is better. The more reach from the same foot print the better. Unless you would want to lift up something with the tip but hey... Nobody does that right?? That would be ilegal...

Must admit a semi can often make much tighter turns than a fixed truck. (if you have the right driver) We have semi's here that can make a U turn in a tunnel where I could not even fit across with a 38m schwing..

Disadvantage with Putz compared to Schwing for me is that Putz builds much more from the eye of a mecanic and schwing more from the eye of an operator. I therefor like schwing better. Mecanic works on a unit maybe some hours every 2/4 weeks.. Operator works with a unit every day for 8/14 hours.. In adition there is to much unnessesary BS on Putz pumps.. And its no use to complain about it.. They will only defend their opinion and never listen to the guys in the field..

55m schwing is better thats why we got rid of or 2 52m putzs. been running a pump for the same company for over 34 years.

what was the prob.s about 52s?

They still need to have their outriggers properly deployed: 

http://concretepumpingvideos.com/videos/615/concrete-pump-accident

Everybody has their own opinion of Schwing vs. Putz. As for your comparison, A 52 trailer mounted Putz is harder to get out of jobsites that are tight. Due to the truck having to turn the opposite way to make the trailer turn. Getting in the job is usually easier.The tractor also has to be straight with trailer during set up to attach counterweight hook. If it is not hooked up, you can rip the 5th wheel right off the truck. As far as pumping with the machines. The 52Z 5 section can't be beat. It has 5" pipe, shorter sections and hardly no bounce. You can pump wide open and watch the hose try to pull itself through its own skin with little boom bounce. The Putz is also rated at 210 yards an hour. But I did 900 yards in 3.5 hours before. 2-3 mixers at pump and never stopped until the end. That is just under 260 an hour on a 1998 model. I want to see a Schwing do that.