Something that has held true for me my whole life with all but a tiny fraction of my trout rod quiver is:
"if the rod doesn't like a regular weight; standard/conventional/traditional taper DT or WF; I don't like the rod." As a result, I try my hardest to buy nothing but moderate to slow taper rods and all I use are standard taper DT's & a couple of standard WF’s for all of my trout fishing.
When I find a line I like, I record its taper on a spreadsheet along with other lines that meet the "standard" description so I can compare my preferred line to other offerings. If I can’t find the specific information on the line I am after, I call or email the manufacturer for that info. When I'm happy, I resist experimenting with something new that comes down the block if I am totally satisfied with what already works. I also NEVER assume I’ll like a line just because it is marketed as a “good old fashioned DT or WF” because you would be surprised at the differences, especially with the front tapers which is a big factor in my preferences.
Excluding the wacky tapers and overweight lines (which I avoid like cheap fortified wine) having a list allows me at a glance to know whether a line will appeal to me based on what I know I already like. That saves me a lot of time & money or asking questions and opens up my eyes to what is out there BECAUSE, it will only be matter of time before a line is discontinued or modified. When that happens, even the line profile info will disappear from the Internet to use for comparisons. I also buy additional favorite lines as insurance when I can get a deal, whether I need them or not.
Buying a fly line today is like shopping for potato chips. It stinks that things have got so complicated and there are so many choices, however for many folks things are better because there are so many line options to dial in a rod’s performance to an individual’s liking.
I’m just glad my rods like plain potato chips…