Today I received a new Cactus v4 Radio Flash Trigger and Receiver set, my compensation for allowing Harvest-One to use a photo of mine in the instructional gallery booklet that will ship with the new trigger set. This product has not yet been released as they are still making final adjustments, but as you can see this kit is a fairly drastic departure from the previous versions of Cactus triggers.
For starters, the trigger now features a small antenna, which can be folded down when not in use. Preliminary tests indicate flawless triggering at 50+ feet (didn't test any further).
Another new feature is that the set is now 16 channel, which is great if you shoot around others who use the same triggers, but not so great if you have 7 v2 receivers, because those are not compatible with the v4 trigger.
The v4 receiver has lost its flimsy pivoting neck, and has exchanged its upright standing position for a pronate position which also allows it to function as a make-shift flash stand. This works great on a perfectly level flat surface, but aside from that serves no real purpose.
The receiver now uses two AAA batteries, which are significantly easier to purchase compared to the CR2 batteries utilized by previous versions. The kit ships with two AAA batteries.
Strobist Info: Shot in a tent box, one bare 150ws studio strobe box left, one at box right, both at full power, triggered with Cactus v2 trigger/receivers.