Yep, try both.
My last bike was a slack angled AM bike and the first time I test rode a mates Trance Advanced 1, I hated it going down hill. Second ride, I flipped and lowered the stem and it completely transformed the ride. Yes, it is more twitchy than my last AM bike due to the slightly steeper head angle and shorter wheelbase but I find that it makes the bike a lot more nimble and it changes direction at will. I am just as confident on the Trance (yep, I ended up buying the same one) as I was on my AM bike going down. Going up, the Trance blows it away. It's light, stiff and climbs superbly. I've owned 3 Horst-Links (FSR) style bikes, two being Specialized and I find the Maestro linkage of the Giant a little more efficient. But that's just me. Line up a test ride on both and see which you prefer. Take the time to set up the shocks to suit your body weight (no point testing a full suspension bike out without the suspension set up correctly) and adjust the stem on each for roughly where you like it. A good shop shouldn't have any issues helping you out with this if they want a sale.
That aside, I say Trance. Great Suspension, sorted frame and better value for money not to mention a warranty service that's second to none.