My son loves them...great arch support!Having had numerous pairs of GT2000's since 2011 I ordered the GT2000 6 pair without second thought. However, I am extremely disappointed in them. They arrived on 5 January and I started training / running in them a few days later. I also own a pair of GT2000 5 and alternate each day between them and the GT2000 6. The mesh is shocking to previous versions. It has no durability whatsoever. The mesh on the top of the trainer is now giving way and holes are appearing! I thought about replacing them but as an experienced runner knew something wasn't right. You can't return them to Amazon as it's been more than 30 days so it's a case of speak to ASICS directly. Apparently they've changed the mesh in the GT2000 6 to make it more breathable and said that they've had mixed feedback. I agree with that as you only need to read through the reviews on here to see that. I usually go through two pairs of trainers with my running a year. The mesh should not start to get holes in in less than two months! Not acceptable in the slightest and would avoid this series and look at the GT2000 5 instead as more durable.I put them on and I thought they were too tight in the toe box 9I like more space for toes). And then I took them for a run... They are absolutely amazing! First 16k run was smooth, achieved faster pace, higher cadence with the same (or less) effort and higher "runefficiency" ever. It is my choice for the next half-marathon and will continue to prepare for the marathon in early Autumn using these and Kayanos. The plan is I will continue workouts using Asics Kayano 24 for longer and slower runs and perhaps for a slow and even marathon race. And GT 2000 6 for tempo workouts and runs up to 10-12k, when I will try to speed up a bit. I just simply can't decide which ones suit me better. Kayano24s look better, but they are less roomy in the toe box and slightly heavier. GTs are lighter (encourage higher cadence with comfortable feel), wider (more stable) and automatically make me want to go faster even during a long run.I switched to the Asics GT2000 series quite a few years ago and have never had any serious or long-term injury since then (apart from some caused by obvious overtraining). Prior to using these I had frequent knee issues. A gait analysis in a running shop showed that while I pronate a little, running in this neutral shoe was better for my feet. The results were immediate and I never looked back. I briefly tried a pair of 'other brand' shoes last year and almost immediately started to have some niggles. So I don't bother any more with anything but these and some trail shoes from Decathlon (which are great, by the way). I'm running more on trails these days and since this is a little less metronomic than road running, maybe the shoe matters less. Still, for marathons or any other road running, I will not use anything but GT2000s. These must be my 10th pair at least?Like others have said the toe mesh is feeble and has developed a hole. I have had the same issue with previous pairs of GT-2000 but after longing periods and they generally fit me well so put up with it and do cover a lot of miles running but this pair has failed much more quickly after a few months and that is me and ASIC finished after this happening too often now. They are not fit for purpose and will look for another supplier/model.Now my third pair of the Ascics GT2xxx series shoe as im a hyperpronator and as always im very pleased with how good they are. And the price i paid for these was really good too. Other colours are a lot more expensive but i dont care what i look like, its all about the comfort and assistance