Johno Smith introduced the Unicender to the New Zealand tree climbing scene about a year ago. It wasn't long before he was suggesting modifications to Unicender designer Morgan Thompson. However, as far as we know, these mods have not been applied to the Unicender now made by Rock Exotica.
When Cornwall Park arborist Russell VanWijingaarden started climbing on the Unicender he could immediately see the benefit of Johno's suggestions. In the same vein as a slack tending pulley in a DbRT system, Russell added a deep sheave pulley to the bottom bar of the Unicender. This allows for one-handed slack tending without generating any friction. The mods' have been carried out on a section of the Unicender which does not provide life support.Russell also uses a short bungee clip to the hand ascender (whereas Johno uses the bike tube) to keep the Unicender under tension during ascent. The Beal Pinch on the connecting carabiner also helps keep everything in-line.
Like Johno, Russell uses the Unicender most days for ascent into the tree. The major benefit of the Unicender as an ascent tool is the ability to descend in a hurry, if required. Talk to either of these two climbers if you want to know more about the features of the Unicender.