I cannot say enough good things about the Intak water bottle. Thermos hit a home run with this product. I first discovered it almost a decade ago when my old beloved water bottle shattered on the concrete, and I embarked on a long search for a water bottle that met a very particular list of requirements. When I found the Intak on sale at Target, I was an immediate convert.

Since that time so many years ago, I have purchased at least 10 of these in a rainbow of colors. One for work, one for each car, several for my husband, and enough to keep one in practically every room in the house. I've broken a few (and immediately replaced them), but considering how much I use (and drop) them I'm surprised it's not more. The main plastic container has never broken, just parts of the lid when they hit the concrete the wrong way. Yes, I drop things a lot.

Pros:
-slim profile to fit in a regular cupholder
-locking ring lets me toss it haphazardly in my purse or backpack without worrying about leaks (and more recently, lets my toddler play with it without spilling all over the floor!)
-attractive design in a variety of transparent and lovely colors
-one-handed operation with fantastic spring-loaded flip top
-loop for carabiner
-good capacity for me to chug all at once if I'm parched, but also holds enough water for an outing without being too heavy
-lightweight BPA-free durable plastic (it's really hard to break these things......)
-not insulated; for me this is a pro, I was looking for the bare minimum weight to allow me to drink my water at room temperature. I don't like cold water.
-Perfect size spout for drinking (with no fiddly straws or anything). I can freely chug water, even lying down, without getting a faceful of water.
-Also has screw-off lid so I can put ice in it (which I almost never do...but it's a good thing if you want ice).
-All silicone seals are easily removed for cleaning, so no icky growth in your straw like other brands.

Cons:
-if you're drinking it while holding in a way that your hand is putting pressure on the cap, it can leak slighly (as the pressure of your hand slighly jostles the seal). However, if you make sure you only hold the main container while drinking, I've never ever ever had a leak (while using or storing)
-not really a "con", but the tracking ring for how many drinks you've taken has never been useful for me.

By the way, we also recently tried one of Thermos's newer "Tritan" models. They are almost identical to the Intak, but the spout is slightly smaller (to its detriment), limiting my drinking rate slightly more than I'd like. We also don't like the Tritan's opening mechanism quite as much, it seems more fiddly and harder to open. So we'll be sticking with the Intak!