So I went and bought new pens/markers to try sine I have been hearing great things about them. Bought a black set of Derwent Graphik Line Markers and a coloured set of their Line Painter pens.
Put the black pens to the test first. Very nice and dark and no ink blobs or spluttering from the pen nibs. The pens flowed well, didn't get stuck on the paper like some other brands can. There were 3 in the pack, 0.1, 0.3, and 0.5 so its easy to get detailed work. Would have been nice to have a brush option to fill in big areas with but I guess you could just use a lot of hatching for that. Would probably get these over the Pitt pens I normally use, the price is about the same and even cheaper in some places with my student discount.
Will review the coloured ones in a few days once I try them on different types of paper.
*edited* Forgot to mention that if the lines from these pens get wet, they will run so if you don't want that to happen, stick to Pitt pens. :)