Would be a good paddle, but is spoilt by the constant tree portages. Pistyll Rhaeadr, Wales' tallest fall about a km above the putin is well worth a visit though.
Takeout at the B4580 bridge in Llanrhaeadr-ym-Mochnant. Head upstream along the small road on river left, and the putin is down a small track at Tyn-y-wern about a km downstream of Pistyll Rhaeadr.
Rainchasers is best experienced as an app.