I've got (and dont ask why)
Custom divers ST1/10w HID. (2002 Purchase)
Dive Rite nimh/10w HID (2004 Purchase)
Halcyon original style Pro4/10w HID (2001 Purchase)
Salvo 21w/13.5Ah HID (newly acquired)
So.. pros and cons.... and no... Im not biased... these are my personal opinions and others may have different experiences.
Custom Divers.
+ VERY secure lid fitting that is just not gonna leak (barrel & face seal)
+ Customer service is excellent (can't emphasise this enough)
+ Bullet proof construction
+ Solid/reliable fast charger
- Worlds wankiest goodman handle
- Non focusable beam
- Lid fitting can be fiddly sometimes
- screw in lid means the power cord gets twisted.
- heavy battery pack (even in water... personal preference issue)
http://www.customdivers.com
Halcyon 10w
+ Cheap batteries to replace
+ focusable light head
+ excellent goodman handle
+ Good charger performance
+ good battery/lid connector
- APPALLING customer service
- just a tad too leak prone (old style latches, now ships with lockable latches)
- Was pricey, now reducing
Note; New style 10w HID has its own raft of pros/cons.
http://www.halcyon.net
Dive Rite nimh/10w
+ simple and VERY compact/light
+ Excellent charger performance
- non focusable light head
The Goodman handle I have is the elastic one... the juries out... so far it seems ok.
Customer service seems ok, mine went back for some checks under warranty and came back within 2 weeks.
http://www.dive-rite.com
Salvo 21w/13.5
(just bought, hasnt been wet, but I've seen them in water)
[Update, has now done a fair bit of in water time, including some nice caving]
+ value for money
+ VERY robust bulb (it got thoroughly squished on the entry to truffe)
+ Good construction (throughout)
+ customer service (so far)
- Still seems to suffer from a not quite perfect charger, you need to plug and unplug it when it claims to be completed.
http://www.divingniknaks.com (UK only, speak to phill.... say hi from Zak!)
http://www.salvodiving.com (US etc)
I've also used a Halycon 18w... Im afraid that thing suffers from fragile bulbs!
One day, I live in the hope that Kowalski will get their act together and sort out that thing they call an umbilical
The other make I've tried out is Sartek, from two dives... my comments;
+ Seems to be well constructed
+ Focusable lighthead
+ well constructed/thought out battery pack/fittings
- Goodman handle didnt work for me.
No one can say "brand x is ideal", since it will depend on your environment/requirements. Having said that, I'd recommend either Salvo or CD in the UK. You need to consider also how much you want to travel with your glorified candle....
One major point, backscatter from powerful lights in UK sea diving can be a significant issue. We found that when diving this past nov in florida caves, the water turbidity was such that a 10w performed better than an 18w.
/Zak
PS. If I've upset anyone, sorry.... Im just relaying my experiences.
PPS. The face seal used in Salvo/Halcyon was originally to allow the SLA's to offgas hydrogen without popping a light can. Im not sure its needed nowadays, with nimh... must check!