sugarmtngal wrote:About to purchase a full dry suit [1], however a vendor
led me to believe 'dry pants' with my dry top
should be efficient-[2]
Well, a Kayaker friend explained to me that
the dry pants will fill up [3]and she recommended
a purchase of a full dry suit.
I have always been dry in a full dry suit,[4] and
have never tried the pants with top.....
Actually my hydroskin pants with underlayers
and a dry top have so far been pretty good![5] Just getting
tired of my legs being wet [6]when having to
scout sections.

Sorry for quoting your entire post, but I drew something from almost every sentence, so I added #s for cross reference.
Full suit IMHO, heres why:
1) So you can afford the full suit if that is your final decision
2) "Cost efficient" - I would agree, but if you can afford the full suit...
3) Possible, but not likely with dry pants that "mate" with your top - I don't think it is a safety issue
4) So, you are OK with the basic "feel" of a full suit; you might not like dry pants + dry top nearly as much. It takes longer to get in because you have to roll the two together to seal near the waist, and the roll creates bulk near your waist, under the spray skirt tunnel, that can reduce your flexibility
5) So you already have a combo that works in warmer weather when you don't want a full suit
6) You just need a full suit, with sewn-in gore-tex (or equivalent material) booties. Then wade without fear or hesitation!
OK, one thing you didn't hint at, so I'll add it - get a relief zipper of some kind. Some women get traditional drop seats, some prefer male relief zippers and carry an "accessory" to make it usable; no personal experience on which is better...