Prior to telling you about the shoe I'd like to give a rough idea of my body type and what I use the shoe for. I'm roughly 5'11" with a slim build and have started a fairly regular (3+ time/week) cross training program to get in shape. As part of this program I will run anywhere from 1 to 3 miles either on a treadmill or with gym workouts. I have tried a few different high end running/cross training brands so I have a pretty good feel for what is out there. Generally, I tend to purchase a shoe that leans toward cross training vs pure running so I was excited to give the Glycerin a try as it is definitely a more running focused shoe.

First thing I noted when putting the Glycerin on was a slightly snug fit from the stretchy top material. After using the shoes for a few weeks this fit has relaxed a little, to more of a 'just right' fit that felt great on the treadmill and on the gym floor. One notable difference from previous shoes that leaned more towards cross-trainers was that the Achilles and heal area height was shorter but not an issue, just different. Final fit note is that as a former Hockey player I struggled with 'lace-bite' on the top of my foot but found that the glycerin 21 shoe tongue provided better cushioning/protection than other shoes I have used recently.

How have the shoes impacted my workout? Being a running focused shoe and the first shoe that I have tried with the large foam sole, I find running and walking to be much more comfortable, and as a result I have been able to train more aggressively here. The one drawback is that the foam sole and stretchy top material do not provide as much support as a cross-trainer would in lateral movements. Would not recommend shuttle runs or aggressive ladder workouts in these.

Odds and Ends: I have the all black version - maybe should have been braver and gone with one of the more colorful options, pretty bland looking. Fit/Finish/Quality are as expected of a premium brand. Sole grip is above average for a running shoe.

Would I buy in the future? Definitely. Despite the limitations in lateral movements the advantages for running comfort are definitely worth it - in the future I plan to have a cross training shoe and a running shoe in my rotation as a result and will coordinate workout plans with shoe choice.

This is the best walking shoe I have ever owned (and I'm 66). I had to stop running around 60, so I can't speak to run performance, but as for long distance walking (3+ miles), I tried on just about every variation of every brand over a month-long search (Asics, Hoka, Saucony, Sketchers, others), and the second I put on this shoe, I realized this was it. Had to order through Dick's to get Blue Opal in 12.5 2E. Best factor is how good the shoe feels, not just light and cushiony, but toe box in 2E is more spacious than most, and shoe much more durable than it appears (on bottom, sides, and mesh top). Tried GTS version, but concerned the extra support on the sides might rub ankle. 12.0 fit fine, but took chance on 12.5 in case I wanted to add insert, 12.5 still perfect. So satisfied, I bought a second pair in Coconut on discount. New Dick's process for trying shoes on in store is cumbersome (but understandable given theft factors), thanks to Dick's for having enough stock in store so I could figure-out best shoe and size for me, plus option to order exact shoe online, excellent free shipping delivery.

I agree with many other reviewers (and feet) that the uppers on these are a problem, whereas the previous Glycerin 20 were far better. I found that the mesh material on the 21 had little flexibility. Most importantly, have a feel inside the shoe right where the tongue is stitched on, near the toes. That threading is incredibly tight and exposed, rubbing against the foot on the metatarsals. I had so much pain due to that design, I returned them and got another pair of 20s. Brooks responded that there is a little piece of foam there. Again, just press there to get a sense what your foot can also experience - said foam is underdesigned, coupled with tight mesh. Other brands' daily trainers in this category have much more flexible uppers, though I love the Brooks Glycerin foam so much. I wish they could solve this upper. At the moment, the 21 is not an option for me.

I've been running in Glycerin the past 5 years or so and buy multiple pairs each season - for me, this is the best version to date. Compared to the 20, they are lighter and have even more cushioning, but not so much that they feel top wobbly. The tongue is better and softer, nearly perfect. The laces are a more spongey material and less like backpack straps. And the bottom profile of the sole is curvier which I think makes for a more pleasant gate. The drop feels great, slightly propelled forward. The cushioning around the heel is beefy and my foot doesn't move around at all. Overall just really solid.

Okay so now that I've told you how great they are I want to make a quick pitch based around my one complaint if there is one - the color ways are still lacking and not up to par with the brilliant engineering of the shoe. Brooks, I would love to join your team designing new color ways - I promise greatness!