No experience with the First Gear pants (read the Revzilla reviews) but I'll pass along a couple observations made recently, as I am also looking for replacement for my Olympia Xmoto pants (wearing out finally).
1) Olympia pants in general fit me much better than others I have tried (Klim, BMW, Revit) because they are designed by the owner (here in the USA) for taller American riders. The other pants were very "short-waisted" and kind of sat on your hips, and if you tried to pull the waist up to YOUR waist it resulted in an instant wedgie.
They just didn't fit properly at all.
2) If you liked the fit and finish of the Ranger pants themselves but just didn't like the thick liner concept (neither did I), do what I do--toss the thick liner and wear a thin separate layer like Underarmor or generic brand of thin lightweight long johns--its all you'll need in cold weather. Those pants are coated to make them waterproof and therefore wind-proof as well, and that thick under-liner is just plain overkill and can become quite hot since those pants don't breathe like un-treated cordura.
Edit: re. the Ranger's inner liner, scissors can remedy that pesky inner "fly gator".
Disclaimer: I am not affiliated with Olympia, just have had great luck with the fit and finish of their stuff.