You can't go wrong with either one.
You just need to know & understand the Rotary Pad designs, The base model will come with Flip Style pad design which gives you 3 different heights, Then you have Round Pads that screw up & down for finer adjustments, Then "Truck, Captured" style pads that are adjustable.
The Flip Style Pads work on a lot of vehicles, Except for some sports cars (Corvette) & some older trucks with wildly different frame elevations (Older Ford Rangers come to mind)
I've lifted Corvette's with my Flip Pads, But had to use Hockey Pucks to clear the rockers (It's much easier to use my Challenger 2-post for Vette's)
The Round Pads have the lowest minimum height, Fine tunable & you can get Stackable Inserts. I would negotiate for the Inserts to be included in the lift purchase as Rotary accessories are Expensive!!
I would only consider the Truck Pads if you only plan to lift Trucks/SUV's, Though they do work on most "Pinch Weld" lift point Cars & Small SUV's.
The Challenger comes with 2-Stage Screw Adjustable Pads & Stackable Inserts, Be aware of the Roll Pin in the lift arms that keeps the pad base still so you can adjust it. There's a notch in the pad base to clear the roll pin, My apprentice likes to stack the pad/Inserts over the roll pin & press it out of the arm while lifting a vehicle. So far I've been able to press the pin/s back into place.
Rotary's "Double S" Columns are VERY ridged & I trust it more lifting heavier trucks.
Challenger uses Aluminum Equalization Cable Pulleys, Like them better than Rotary's Plastic Pulleys....Though I haven't had any issues with them.
Both will require periodic Anchor Bolt retorquing & Equalization Cable Adjustment.....The Locks need to sound off in unison as you raise a vehicle, Adjustments will become less frequent as the cables get broke-in.
It would be difficult for me to choose between my Rotary & my Challenger, Thankfully I don't need to.
