From my personal experience it matters more who you get it from than what you decide to get.
Do your homework, look at online/fb portfolio's of artists you are considering, try to fault each image you see of theirs, remember this is their showcase work, the stuff they are so proud of they shared it online.
So look at line work, or rather incomplete or wobbly lines, look at colour and shading, where the shading meets the line.
One of the most said and most important thing about tattoo's are : Cheap Tattoo's and Good and Good tattoo's aint cheap.
Also look at scarring after it's healed. I see so many tattoos where the artist has gone too deep & left a visible scarred outline.
I would definitely go to Metal Machine in Cape Town again,.. if I could find a design I like. 12 years later mine still looks good. barely faded