I have found all of the top end nylon brands to be of good quality and give similar performance. I mainly use 20-25lb line because it stands up to the abrasion of the east coast beaches.
I typically avoid ‘black magic’ tackle mainly because they are a brand rather then a manufacturer, I have no idea who they get their hooks or line from and prefer to buy it from a manufacturer brand. In saying that, I have been using Black Magic flouro Leader material and I can not fault it.
My current line is Pioneer FLEXLINE (made by Sufix I believe), It was $25 for a 770m spool, so $12 per reel. My next line might be the ‘Sufix’ Surfcaster one.