First off, let me start by saying I used this shoe on the last leg of my Appalachian Trail thru-hike (White Mountains to Katahdin), so I was probably pushing this little bad-boy to its limits! I'm sure the average user wouldn't have treated the shoe as I had to.
That being said, I am very glad I went with this shoe. I chose it online based on what I thought I would need at the time: lightweight, something narrow (form-fitting) enougth to allow me to stick my foot between boulders, comfortable for days of walking at a time. I also needed a shoe that could dry out easily, as Maine is known for being a place you get your feet wet.
I was very happy that I'd gone with this shoe. My feet never hurt, ever. The sole is AMAZING, and to this day has enough tread on it look nearly new (and this after a couple months of walking on pure rock!). The only "flaw" I found was that BOTH the mesh uppers tore in exactly the same spot (right along the toe guard)... but that was due to the roughness of the terrain and snagging roots, so I'm sure that wouldn't really be that much of a concern for the general consumer.
In all, a hearty little shoe. I couldn't have been happier.

This is my first pair of Merrells after several pairs of New Balance trail runners and all I can say is that I wish I had tried Merrells sooner. The four way cushioning offers everything it promises. I wear them to the gym six days a week, for strength training and cardio (mostly running), and use them for street running about twice a week. They provide excellent support for running and have yet to fail me during intense sets of lateral movement.
They were comfortable right out of the box--no break-in period or blisters--and I'm not aching to get out of them once my work out's done. These shoes are incredibly lightweight, very breathable and oh-so comfortable. I've put them through the routine mentioned above for about 4 months now, with no significant signs of wear.
They also happen to be very cute. I'm planning on buying another pair, just in case Merrell discontinues them before my current pair wears out. Love them!

I purchased these Merrell's just two days before a trip to the NW and walking through the airport was enough to break them in! I spent three days walking the hills in downtown Seattle non-stop. My feet felt so great in the Siren's that I ran the Whidbey Island 1/2 Marathon in them and followed it up with two days of Portland exploration. My entire trip was foot-ache and blister free and after six months of continuous ware and tear - they're LITERALLY as good as new and still sexy as h-e-l-l! They don't call them Siren's for nothing! If I'm not in heels, I'm in Merrell's!