Some random points on the subject:
1) The selection of the stabiliser vs roller reamer is dependent on the requirement. In this case the selection criteria have not really moved on, though maybe the understanding has.
2) When selecting the stabiliser choose the blocks for the application, i.e. if you have one for back reaming choose one with an upward uni-directional block, ledging and shocks & vibrations bi-directional, etc. In general the bi-directional block tends to be selected without any thought. Also be aware that blocks can come in different 'hardnesses' commonly based on IADC bit codes.
3) A full gauge roller reamer will tend to act as an undergauge stabiliser
4) There was some discussion on the subject of roller reamers on the SPE TIG about a year or more ago in which some of the results of a multivendor test were published by Al Scott at Marathon. Though the test was performed in the early 1990s the findings are still valid today.
5) Personal experience in directional wells mainly suggests that the most common causes of failure are related to incorrect placement, poor maintenance (or untrained crews) and running out of specification. My personal bug bear has always been the incorrect placement since this is relatively easy to sort out as primarily its related to balancing the collar mass above and below to minimise the off axis rotation and cross loading on the bearings of the roller reamer. In addition always be aware if you are selecting a roller reamer it has a relatively short life compared to a stabiliser.
5) In most of the environments I've had to run roller reamers in (medium - high shock environments) I have never run without a retention system that I or my colleagues have been through with the vendor to identify potential failure modes. Infact I would never run without a retention system, quite simply in a market where rotating components below the rotary table are becoming a rarity we tend to forget how to run it to prevent catastrophic failure......
Having performed many runs with roller reamers (primarily logo'd with a spider
) I have had no major problems, occasionally bearings fail but a good retention system prevents any issues. Along with this though I don't recommend changing blocks out on the wellsite, I would always ensure staff are available who have received recent training to do this, and have spoken to the vendor about condition monitoring. I would also suggest that if we pay as little attention to roller reamer design and operation as we do to stabiliser design, provision and operation it is not surprising that failures occur to the one with moving parts!