I am deciding whether to get the YYF Space Cowboy or the YYF Nightmare. I know that they are both Bi-Metal yoyos.
Which yoyo will be more stable and have a good weight to it?
Please help me decide. 
This post is gonna be moved here in a second to another part of the forum, just a friendly heads up.
Also, both will fit the bill nicely from what ive heard. Its gonna be a 50/50 of one or the other. Nightmare is a hard V shape the cowboy is a bit softer shape. Both will slay in the stability and spin time dept.
Nightmare is 64g
cowboy 66.2g
Personally, bimetals aren’t my thing. Sorry for bias.
If you do choose to get a bimetal, I think that the nightmare is your best bet. Space cowboys seem very heavy to me-- this can be good if you like heavy throws, but if you don’t… Space cowboys also have kickback. Its not extreme, but it’s definitely there. The space cowboy is also more expensive. I haven’t played a nightmare, but I think that the kickback has been fixed. I’m not sure about the heaviness, all rim weighted throws seem really heavy to me.
Seriously though, unless you’re dead set on a bimetal, just save up a little more and get a scout or something.
I own both and both are really stable. It all boils down to if you prefer an H-shape or a V-shape, and if you prefer something light and fast or something that plays a little heavier.