In reply to Jus:
I've got a massive rack of WC Helium draws (bought second hand) and they are categorically not worth the extra money compared with DMM Spectre 2s if you are paying anything close to the normal retail price for them. Brilliant krabs but just not twice as good as the Spectres.
The two best value for money options currently available have already been mentioned:
Full size - DMM Spectre 2
Lightweight - Ocun Kestrel
Lots of other lovely options available like the Petzl Ange (a climbing partner last year was sponsored by Petzl) but like Heliums they are hard to recommend given how expensive they are.
HTH