Hmm, it appears some misconceptions remain regarding the age old question of DT vs. WF.

Most lines are made to AFFTA weight standards which means that the line must weigh a certain amount in the first 30 ft., excluding any level TIP section. The taper IS included in the weight.

Most DT and WF lines have very similar front tapers, there is no generalization that can be made regarding tapers that would be accurate. Some DTs have short tapers, some long, as do WFs. Assuming that a DT and WF line have the same taper, they will cast exactly the same until the rear taper of the WF line is out of the rod tip. There is no way anyone could tell the difference between these lines except that the WF caster would be holding smaller line in his hand than the DT caster.

The 30 ft. length is often mentioned when talking about roll casting WFs. This length means nothing in most cases, except that it is the length measured. Nearly all WF lines have heads that are longer than 30 ft. Another thing to remember is that roll cast distance must include leader and rod length. A WF line with a 30 ft. head and cast with 9 ft. rod and 9 ft. leader will roll cast effectively to 48 ft. (30+9+9). So, a typical WF line with a 38 ft. head (common for a 5 wt. "trout" line)will roll cast effectively to well over 50 ft. Most casters cannot roll cast that far so it makes no difference for most anglers which taper they roll cast.

DT lines can be cast extreme distances by talented casters. Some casters are capable of carrying an entire DT line in the air, making it a very long ST, in essence. Yes, the extra weight of the long, large dia. line loads the rod more, but good casters know to open their rod arc and make their strokes very smooth. Dropping 2-3 line sizes lighter than the rod is rated for makes casting DTs a long ways even easier.

For fishing use most anglers are better off with a WF line, unless distance beyond 50 ft. is rarely needed. Beyond that distance, being able to shoot the small diameter running line of a WF makes long fishing distances easier to achieve.

If a DT and WF line have the same front taper, their "weighted zone" is the same, until you get to the rear taper of the WF. Beyond that point, the DT will remain heavier due to its larger diameter. It is easy to see where the weight in a line is, just look at the profile, where it is big, it is heavy, where it is small, it is light. This assuming lines of a single specific gravity, not sinking tip lines.

Joe, switching to DT lines for your short distance casting will gain you no benefit. Again assuming similar tapers, there will be no difference in how the two designs will cast at short range. As much as I'd like to sell more lines, save your money for a casting lesson if you're having trouble!

The average +- weight tolerance is about 5%, not 10%. A very talented caster might be able to tell the difference between a line made at either end of the tolerance, but for most people they will feel and perform exactly the same. Certainly it makes sense to try different lines on your rods to see whether you might like a 4 wt. or 6 wt. better than a 5, but usually performance problems originate with the caster, not the gear. If you question this, give your troublesome gear to a better caster to get his/her opinion.

I hope this doesn't just confuse the issue more........
Bruce