I have and use lots of sinking lines. I stick with SA simply because that was the only brand available to me at my local store. I have #5FS types 1 thru 6. If you are using the lines for timed sinks I think you should stick to the same brand. I got a different #5 full sink in type II and it sunk at a different rate than my SA type II did.

I cast toward shoals a lot and the around $50.00 Sa line casts well. The Cheap walmart stuff resembles a slinky in cooler waters.

For trolling I do use the cheaper $10.00 sinking line from wal mart to save my good ones for casting. The wal mart line doesn't have a sink rate on the box but At the lake I compared the sink rate with My SA lines and it sank at about a type II.
I like to troll the same speed all the time, so I use different type sink rates to regulate how deep I am. But If you have only one sinking line you have to vary the speed to get the right depth.

If you cast one of the cheapter thicker lines all day, you will realize the value of a better brand.IMO