From a value perspective, I think it's a good deal, assuming its in good shape. Like you I have a 686+ and a 627 pro ( that I shoot in USPSA) . If I was offered the trade, I'd probably do it, as the L frame is my favorite S&W wheel gun. Besides, I always wanted one of the factory ported versions.
On the S&W forum, lots of positive feedback on the L, K and F comps.