That is good that you are happy with what you have got. It is expensive hobby. I just pointed on the fact, that you could get it cheaper.

But I don't get what do you mean by saying "much better beam "...IF you mean divergence, than it is quite obviously metter of how manufactures state them. Half-angle or full-angle...they can say anything. So finally it is about what you get and as you probably did not get any ours 640nm it is not right to say "much better beam " , is it.

Also IF there would be one more laser diode in one module that the other (and this is only speculation), that would certainly influence the divergence, temperature and lifetime.

Can not wait to see it at next meet and I will try to get over some KVANT demo stuff as well.