I am about to send for 3 lines to match my new rod, the rod is rated #7/8 and i can't make up my mind which line to order, and have ordered and cancelled on line 3 times!! thought i'd ask you guys!
A test of the rod in T+S stated it cast a DT7 and WF& with authority and finesse and when used with a AHD8 it bent a bit more but still cast all the line easily.
Would you guys go for the "Authority and finesse #7 or go for the #8 for more distance?.......the rod is going to be my general large stillwater rod.

In theory mate and according to the AFTMA system, a rod is rated at being able to aerialise and cast 10 yards of the corresponding line.

In practice and in reasonably skilled hands you will be able to cast both weight lines.

Personally, if you are not an expert caster, I would go for the heavier line as even with a short amount out it will make the rod load up better.

Over the years I have owned rods that have been terrible for the line weight they have been rated for.

I have a 7 weight Greys Platinum XD that is a very fast action. It is much stiffer than some 9 weights I have owned. It chucks an 8 weight shooting head an incredible distance. But then I am quite a good caster and can make adjustments during my casting that many can't.

Go for the slightly heavier line Paul.

Oh and by the way Paul, Graham was advised by a pro to put a 7 weight line on his 6 weight Sage rod.

He was casting much better the last time I saw him at the fish-in.

Thanks for that Ron......looks like its Snowbee float, inter(clear) and fast sinking in #8 is going on the spools.

Paul, what's the rod you have?

I remember Ron saying that his Greyflex rod was a #6/7 and felt overloaded by a #7 line but handled a #6 well.

Have you tried the rod with both lines on it yet? IMHO, I would try casting both weights of line before I made up my mind. As Ron says, "in reasonably skilled hands you will be able to cast both weight lines". I know Ron is a good caster and, as he says, can make the adjustments he needs to his casting stroke as he needs to. I'm not at that stage yet and it takes me a while to get used to different weight lines on the same rod, more so if I'm using a #6 line on one rod and a #7 on the other.

Give it a go before you finally decide as reviews in magazines are carried out by very competent casters, sometimes with a bit of bias thrown in for good measure.

Adrian,
The rod is a 10ft #7/8....built on a harrison blank........thought this flyfishing caper was going to be easy after having to have a barrage of coarse rods!!! now i find i need a barrage of fly rods and reels!! my missus is gonna kill me!

Does a #8 cast better than a #7 based on the rod write up?.......may be expensive finding out!

Normally if a rod is built to a #7/8 spec then it should handle both lines well enough, but there are instances, such as Ron's review where they don't.

Do you know anyone close enough to you who you could borrow #7 and an #8 line from and give them both a try?

Also, the lighter of the two lines are normally the better ones for distance casting and the heavier ones better for close in work. Reason being, as I am lead to believe, is that you can aerialise more line with the lighter line thereby allowing you to cast further. Again, I may be wrong.

Let us know how you get on.

The truth is that all the talk is subjective and to be honest the answer lies with you and your casting style. The best advice is if you have a mate who has the lines you are interested in then ask if you can give them a try as Adrian advised but on your rod. You will Know within about 5-10 minutes of fishing with them if you get on with the line or not. If you can't borrow from a friend then you will have to bite the bullet and purchase at least one line. Personally i would go for the DT7 Floating as this gives you more options. But there is no straightfoward answer to this question as there are so many variables-sorry about that.

You will get away with a 7 in the fast sink as the line is thinner and will shoot better. With regards to the floater i would as been suggested try if you can.