Hi, I am looking at purchasing adjustable dumbbells and was wondering if anyone has used the Ironmaster Quicklock Dumbbells for STS and other Cathe workouts. If so, do you like them and are they easy enough to change weights during the rest periods for Mesocycles 2 and 3? I live in New Zealand and unfortunately we don't have PowerBlock dumbbells or many other brands available here and they are too expensive to ship from overseas. The only other brand we seem to have here is Bowflex which is a similar price to the Ironmaster, however I have read some bad reviews about Bowflex with weights falling off.