I have one on both my bikes. Swift on the Aurora, Swallow on the Sputnik. I started with a B17, but it didn't suit my riding position, so I switched up. I've had the Swift for a little over a year, so it's got some mileage on it. It feels pretty good. I've only had the Swallow a little over a month, but it felt more comfy than the swift out of the box. I think they're worth it, obviously..
wallbike.com has a 6 month return policy if you want to try one. If you like it, cool, if not, you'll just be out the shipping costs.
"6 Month UNCONDITIONAL SATISFACTION GUARANTEE - new BROOKS saddles. Return your new saddle at any time within six-months of the ship date for a full refund of the price of the saddle. Shipping will not be refunded unless there is a manufacturing defect that would make the return a factory warranty issue"