They feel very spongy until you get used to them – there’s no hard thunk the way there is with discs or rim brakes. But they are very powerful and last for ever.
I have Sturmey Archer hub brakes on my Charge Steamer. Not sure if they’re roller or not tbh. It seems impossible to lock them but they do stop it ok. The whole bike weighs a ton, though, and I suspect the drums don’t help.
They’re quite heavy but work well and last just about forever, but can accumulate grit and sand inside because they are not really sealed.
They are like BB7s and drum brakes in that they need good cabling to work properly. Any flex in the cable or levers and the brake feels spongy.
You’re not supposed to dismantle them, but
Bear in mind you need the appropriate Shimano hub to go with them – it’s a shame they don’t use CentreLock so they could be used on a wider range of hubs.
For the equivalent weight, I’d sooner use Sturmey-Archer drums but the ingress of dirt and sand on the roller brakes can be sorted by flushing them out with fresh grease.
If a sealed roller was made, it could be the perfect mtb brake. Filled with grease there’s nothing that will wear out in the life of the bike and it would be pretty immersion proof because the grease would fill all the voids.
I’ve had them on my commuter for the last 7-8 years. Just need a little grease every 6 months or so. No sign of them wearing out yet. I have the IM70 models.
Great performance but a very different feel to discs/calipers/V brakes. Heavy and cheap but maintenance free. I have a dynohub front (DH-3R30), and 8 speed nexus at the rear (SG-8R36 – same as alfine 8 speed inside with good seals). Whole bike weighs 15kg with a steel duster frame but it is only for 3.5 miles each way every day and excellent training! Almost zero maintenance the whole thing.
Got them on a dutch shopper for town duties. Never touched them and they work perfectly, even in the rain. Bike lived outside for the first three yeas of its life. For commuting and pottering I think they are perfect. Feel takes a little getting used to.