First, Loomis rods' power ratings are only only references for the particular style. A rating of 2 in a HSR is different than a STR. They do state that.

Most people that are selling Loomis rods won't tell you that a GL2 is the strongest rod they build. More expensive equals lighter rod. Lighter rod equals less fatigue. More sensitivity is the key though. I have used 1025's in both IMX and GL2. They are not comparable. The GL2 is like a truck. It's sluggish but made for abuse. The IMX is a Ferarri. Killer handling but doesn't take mileage well. The happy medium is the GL3. Very strong, yet sensitive. I love my 1024 in the GL3. Probably my favorite.

As for your question between the 1084 and 1025, the 1025 would be my pick. However your observation on the 1025 being over rated and the 1084 being under rated could be because of the way the extra 6" soaks up more energy from the fish.

I do agree with stlhdr1 about the line ratings. The 1025 is labeled as a 8-17 but is better suited for 12-20.

~Just my observations