Yes to all Sam's points above.. I think trotting and Stillwater fishing have different requirements, and then there's the "light" and "heavy" sides of both disciplines...
(Judging from some of Sam's other posts on float rods, I suspect he'd have something like four or five categories between light and heavy, with a rod or two to cover each and every scenario!)
If you've got the budget to be considering a pair of GTIs then I suspect there's a lot of other choice available to you. However, the trouble with float rods is that it's incredibly subjective as to what constitutes a "good" one, and what floats someone's boat in terms of weight, action, recovery... well, someone else would hate it.
Also, just to confuse matters... manufacturers have a habit of trying to label everything to the nth degree.... so that "12 foot power carp waggler" rod might actually be just what you've been looking for to trot for barbel and chub on a small stream. But the honest label of "relatively powerful semi-through action float rod, max 8lb line" won't win them any marketing awards will it?
Good luck. Let us know what conclusions you come to.
For my part, I do also use two float rods for about 95% of my float fishing. For Stillwater work, which for me is generally relatively light line silvers/ tench/ perch but the occasional carpy intruder... I use a daiwa aqualite 13 foot waggler. Very light, easy to handle, makes catching anything fun. And then on running water (Sam will cringe at this.....
) a Shakespeare Mach 3 waggler rod, which never sees a waggler but is set up with a centrepin and handles that very nicely. It's still a relatively modern through actioned rod but it is crisper on the strike than the daiwa, possibly 3 quarters of an ounce heavier but still pretty light (170-something grams I think?) and as you get in to the curve it has a little bit more oomph, which makes subduing 4lb-plus chub on a fast flowing river a doddle.