Been meaning to write this for a while - on the end of this thread seems a good a place as any.
I've recently changed lights from a Bisun to a Custom duo and though others might be interested in my comparison.
First thing I should say is that I was very happy with my Bisun light (basic Z3 model inserted into a speleotechnic headlite which cost ~?40) and the reason for changing was simply to move to a battery system which works off AA batteries. The first consideration was to buy a duo from ebay and wire the battery box into the headlite unit using the bisun. Unfortunately duo's are sealed units which don't want to give up their wiring at either end! The next option was to cut the wire and fit it into the headlite as the wires can easily be removed from these. This however was flawed because it would leave me with a wire ~ 1 inch too short. I didn't want to muck around with connectors, so it was option 3... fit the duo to my helmet and buy a new light. This concerned me (and still does) as that crappy plastic hinge by which its held on looks light its only going to last 5 mins! I'm considering some epoxy to ensure it lasts (anyone had problems or done anything to strengthen?). I don't care if it no longer moves as I only find this an annoying feature.
So what should I spend my dosh on?
The only complaint I really had with the bisun was that there was no low power setting for emergencies / not blinding people when stood around. This, however was completely my fault for buying the cheapest model which did not have this function (all the others did). Having caved off halogen bulbs prior to this considering a 'less light' option at the time felt stupid! So, being simple minded, all I felt I needed from a new light was a low setting, and then a spot & flood (similar to the bisun). I should add I have a couple of those 1000+ lumen ebay torches cable tied to my helmet for those occasions when more is better.
I looked at both the Bisun Flexitwin and the custom duo omni. Went for the Custom duo for the following reasons:
1. Less settings (I don't like complicated)
2. Custom duo was ?5 cheaper (yep I'm still tight)
3. The Custom duo had a higher spec (quoted output in lumens).
Comments so far (done 5 or 6 trips now), comparing old (Bisun Z3 in a headlite) and new (Custom duo Omni):
Given the two lights aren't exactly like for like, I'm not really sure this is a fair comparison, however it might be useful or interesting for someone.
1. The bisun spot light was significantly better reaching a much greater distance with a tighter beam. This was very noticable straight away.
2. The Custom duo led colour is more yellow which makes the cave look less grey (sounds mad, but I much prefer the warmer colour).
3. Despite trying each setting I've only found a use for the dim flood, medium flood and the high setting (which gives the brightest spot light). I really like the spot / flood combined on the brightest setting rather than the choice of one or the other on the bisun. The medium flood is perfect for caving on and the dim flood for general chitchat / hanging around.
4. Overall the Custom duo is more powerful (not exactly a surprise given the difference in spec) and on the high setting is plenty bright enough to give decent light in big bits of passage (tested in Aggy), whereas I'd never quite felt this was the case with the less powerful bisun. I should add the ebay torches make both look dim though!
The whole lot cost just under ?100. After a couple of trips, one in particular one where I got a mate to use my old light, I've come to the conclusion it was well worth the money leaving me with something much better than I had before. Most importantly I can now use AA batteries and not worry about those damn silly rechargeable packs which are an arse when the inners die (soldering iron and mastic required) and the need for a charger with a custom fitting (I've killed two of those over the last ten years trying to charged knackered batteries).
Hope this is helpful for someone.
Tim
