I've had mine about 20 years or so. I believe it's format (150mm) is the pick of all the Rotex family. Yes, sometimes it's difficult to control. Atop a ladder stripping weatherboards it's downright dangerous, with the papers slipping between the boards & wrenching the tool from the operators grip! Feathering the speed and juggling the pad & paper selection helps, but doesn't eliminate the characteristic. The later version offers pad edge protectors to alleviate this, but in doing so effectively precludes access to those board interfaces.
If you think that the RO 150 is a bit of a handful, the smaller iterations are worse. The smaller pad footprint of the 125 & 90 make the jumping phenomenon more pronounced, which when combined with the tall profile & "compromised" ergonomics of the RO 90 in particular makes for an all but unusable tool that will behave erratically & unpredictably in rotary mode. To try to minimise the damage wrought by this particularly nasty little beast one requires a two-handed death-grip and much less aggressive abrasive grits that obviously won't perform the required task as efficiently. For delicate work like multipane windows in situ, staircase renovation or valuable antique or delicate furniture it's all but useless, ironic considering this is supposedly the tool's forte! The 150 by contrast, when setup to perform at its best, requires a much less tiring & more efficient, looser two-handed stance to control which is less likely to damage substrates.
The RO 150's best features are its excellent dust extraction & pad system, with the 3-way combo of soft, medium & hard densities providing an appropriate degree of resilience for most contingencies. The 2 keyways on the shaft & beefy M8 grub screw offers positive & secure location: the later model with bayonet pad fitting will eventually loosen its pad grip. One operator I know was so frustrated with his pads regularly falling/vibrating off his machine that he needed to resort to the extreme measure of gluing his pads on! The downside of a screwed pad is that the grub screw will over time allow minute dust & resin into the screw threads, which with time & heat will effectively "seize" the screw into its thread, creating a type of artificial "Loctite". Occasional loosening & retightening the grub screw eliminates this phenomenon.
The pad format allows interchange between other Festo/ol (ETS) pads & other brand's products too, meaning that you're not restricted to the Festo/ol 9+ hole sandpaper system, and that you can also use (with appropriate pad protectors to save your velcro hooks) the brilliant Mirka & DeWalt Abranet & Webrax discs too, plus generic 6-hole papers such as may be found at any half decent hardware store.
Aside from the pad protectors, I feel that the change to the newest style Rotex was actually a step backwards in design.
