So again, I receive a message asking advice on the simplest thing and respond with overwhelming depth. Check out the latest on my personal approach to matching lines to common angling scenarios...
"Hey Chris. Question. I have recently bought a new rod and I'm starting to experiment with lines to match. Without having to spend a fortune on lines that may not be right can you offer any advice?"
"Hey Jason, chur for touching base. Firstly I dont see the point in over lining a rod or using a 'half weight heavier' line to turn over longer leaders or for loading on short casts in general trout fishing situations... If a top rod manufacturer rates their rod a 5wt and you cant cast 20' - 60' + with a 5wt line then its time to work on your technique, regardless of leader length. Learn to adjust your stroke length according to the length of the line, and casting arc to match the flex in the rod. Apply force to the stroke accordingly... While some do find benefits in more agressive, overweighted lines they're personally not for me or the lowland, and backcountry angling situations here in the lower South Island IMO...
I've fished the Scott Radian range extensively since its release in 2013 and have run numerous lines through their guides, so will use this as an example as follows.
My go to line for the 905 Radian is the 5wt Airflo Elite. It totally handles not only presentation situations such as found on the Mataura, but bowls over uglies and streamers when needed on the Oreti without a fault. A modern fast 5wt will deal to the wind as well as a 6wt all things given, and the radian generates more than enough line speed to roll out the elite whenever and however required. Personally I think the Elite is a sweet match for radian for the vast majority of conditions and is what I recommend for those comfortable with their ability.
For clients, and those without as practised a technique as others the Airflo Bandit provides that little more punch to assist with wind and long leader roll over. It too is a pretty sweet match for the Radian but for me personally the elite gets shit done.
On the 906 Radian I personally like the Airflo Hero. If I'm fishing a 6wt then it's because I'm bombing big nymphs, or streamers all day. It means rivers are full and maybe the nor wester is pumping and this combo makes it a little easier to deal with over and over. What I lose in finesse, I get back in the enjoyment of casting in such conditions and I'm not busting my ass to make things happen over and over again. I dont generally go for a presentation taper on my 6 wts as that's not what I use a 6wt for... For me its a 'meat stick'. Smashing heavy tungsten and streamers... Again the Bandit offers that crossover between presentation and 'turn big shit over' and performs sweet on the 906 Radian too. The Hero however is my favourite specialist backcountry line, and big water set up.
In my pack I always carry an Airflo Streamer Max. Some pools and / or tricky currents just need that little extra depth and those deeper pools you saw on the way upstream and KNOW will hold fish, probably do, and so getting down and dirty with a Dores Mr Glister and the DI7 tip of the streamer max can often wet the net on the way back to the car...
Phew.... Hope that gives you an idea on my approach mate: good, practised casting technique is king, but there are a few line options out there if you don't feel it happening, or have a specific application in mind. Holla if you have questions or need a follow up.