The c6 works but it is not the most efficient. But then again its $8
The host doesnt make the efficiency.......thats dependent on the driver and diode. The heat sink has varying heat absorption efficiency. Aluminum has decent heat absorption, copper is much better (might be the best available to use hobbyists), titanium (IMO) is in the middle of those too BUT is also a lot more expensive and IMO looks much better but none of them look bad.
I believe you are meaning efficiency as the heat management of the host but in reality the heat sink is what does 95% of that. If that is the case then I'd personally go with copper if you are on a budget and NEED good heat sinking. Aluminum will do for lower powered builds but once you get into the heat monsters (1.8W+ 445nm) then you need to switch to copper OR get a larger host to fit a larger heat sink.
Just for an example; I have a MagLite laser with a 9mm diode. It does 3.2W all day BUT has an aluminum heat sink. Based on my above info you'd think aluminum wouldnt be good for this monster BUT since it is such a massive chunk of heat sinking the laser can easily handle a 5 min duty cycle with no issues. HOWEVER, if that same diode and driver were in a C6 with aluminum heat sink, it would be struggling to do 30 second duty cycles........hope that helps :beer:
You should be fine with aluminum for a 405nm build. Id be okay with that if I built it. Thr anodized heat sink is only for looks. It doesnt add or sutract anything significant from the heat absorption properties. Its not a coating so it doesnt add anything, it is dying the metal itself. Technically it is a coating but its not like if you painted it and it added a layer of crap that made heatsinking worst
I think mikes(Mrcrouse) heatsinks for his 501B kits($20) are a little larger than the C6 sinks but not by a lot. If you want under 10$ host a C6 is the best you will find.
If you step up to $50-75 Look into some of sinners hosts.