I've been running in the Mr P shoes for over 5 years now. I reckon they have to be as fast as the Adidas shoes I was running in 20 years ago. Ran a 2:41 marathon in a pair of Maxed and sub-17:30 5km TT's. I don't think it's the shoes holding me back, although I am also pretty sure that my times would be quicker in the next%. Doubt I'd be much quicker in another brand's 'normal' shoes.
I buy a few pairs at a time. Not much info on the shoes and I often buy the ones labeled 'gym' shoes too not just the 'running' ones. I know what works for me. I eyeball the drop and stack height and check flexibility of the sole. And try them on for comfort. I've even bought a few pairs at a time online and then just return the ones I don't like when they arrive. I think there are 2 or 3 pairs that didn't work for me for running, but I am still able to use them for casual wear. A few pairs are quite soft in the forefoot, which makes them not great over longer distances. And for proper trail running and longer trails, I've now learnt you can't beat a proper trail shoe (after doing a few 40 - 60km mountain runs in my Maxed trail and road running shoes). For road running and shorter easy trails there's nothing wrong with my Mr P shoes. I have got to over 1000km in a few pairs, but I don't feel that I have to get crazy mileage out of them because some of my older pairs only cost R300 or less. I like being able to rotate between different pairs with different uppers and lowers every day of the week if I want to.
I got the new Zeus carbon plate shoe about 2 weeks ago and did a marathon in the Cradle with them basically out of the box. First half was great, but my legs fell apart in the harder second half and ended a few seconds over 3 hours after aiming for about a 2:50. I don't think any brand of shoes would have saved me! I am really impressed with the feel and comfort of the upper and laces of the Zeus. I think they're possibly the most comfortable shoes I've ever run in. The carbon plate thing had me confused when I looked under the shoe and saw the metal weave, but if you look under the inner sole you can see a small carbon plate there. I don't know if it makes any difference in these shoes.
I initially wasn't going to buy the Zeus because of the increased price tag now on the newer Maxed shoes - I first went to try on shoes from every other brand, because I thought at that price I could just by a big brand shoe for not much more - but after trying on a whole lot of shoes and then trying on the Zeus it was the most comfortable and still half to 2/3 cheaper than everything else I tried on. I also ended up with a pair of the Elite Nation all white (running) 'gym' shoes 🙈 and really like the feel of the new Marathon Racer so far.