I switched from the Saucony Progrid Guide 3s to the Saucony Progrid Guide 4s when I got new shoes a few months ago. I was hesitant. The various pairs of Sauconys I've had over the years have treated me well, but I'd heard so-so things about the Guide 4s. Such as changes to the toebox and poor construction. When I got refitted, my running store recommended not changing my shoes. OK then.
From left to right, the new Guide 4, old Guide 4, and old Guide 3.
The heel wear was about the same.
I haven't noticed a big difference between the Guide 3s and the Guide 4s. I ran a half marathon in the rain about a week after getting the Guide 4s. No problems at all. Thumbs up on that front. I used to get soreness in my toenails after very long runs, generally anything longer than 15 miles or so. I don't have that problem with the Guide 4s. So the toebox seems to work for me. Thumbs up on that front too.
Buuuuut, there's a problem. The Guide 4s are not the same quality as the Guide 3s. My first pair of Guide 4s lasted for a whopping 2 months. My Guide 3s had be lasting 3-4 months. Granted, my mileage increased, so the Guide 4s should have worn out faster. But it wasn't just the cushioning. The shoes were starting to fall apart. More wear than normal on the soles. The inside of the shoe around the heel and ankle were disintegrating. That didn't happen with the Guide 3s. I'm not sure I'd go as far as call it poor construction, but it is definitely lesser quality. Thumbs down on that front.
From left to right, the old Guide 3, old Guide 4, and new Guide 4. Those are some worn treads.
Inside the shoe. The Guide 4 didn't hold up as well as the Guide 3.
I bought another pair of Guide 4s, so I guess the Guide 4s are mostly good. We'll see if the second pair holds up any better.
Aaaand, no sooner did I buy another pair of Guide 4s than I found out the Guide 5s are coming out in November. Huh. Maybe there is a reason for that? The Guide 4s only came out in February, so they did not last very long. I wish I had known about the Guide 5s, though. I would have waited.