It's a terrible monitor at any price. The presence of PWM alone is enough of a reason to completely discard this monitor.
To be fair, you really haven't owned anything else to know better.
I own this monitor and 2 others of the same model just with 60 hz and there is absolutely no problem with it and would recommend it at this price.
There are better alternatives around £200 price point. Do not cheap out on your eyes, eyesight is the most valuable sense humans poses, and is the easiest to lose.
If you'd like something that looks good and 144Hz, then I'd suggest you look for deals on Samsung VA panels. I got this monitor new from eBuyer on a deal for £180. To be honest though, you just can't spend that much money on a 1070Ti and not be prepared to spend the money for a monitor that can justify its performance. £175 is really hard to get any worthwhile 144Hz monitor unless you find a really good deal, perhaps like I did. Edit: That said, there's this monitor for £213 with a VA panel if you can stretch a bit. I don't know much about the monitor itself, however.