Hotels in London are expensive so in the end everything comes down to price. The hotel is pretty cheap for the area so you can't expect luxury. Once you realise that then I think the hotel is pretty good. The location is super, right on the high street and opposite the corner of Kensington gardens. The entrance is tiny, you'll miss it first time. It's just the width of an ordinary door then you go straight up some narrow stairs, the same sort of width as an ordinary house and then the rest of the hotel is on the floors above.
The rooms are an OK size, the bathroom is small, but serviceable and the shower was good and powerful. The windows have secondary glazing which is good at keeping the noise out but makes the room very stuffy. The air-conditioning wasn't really up to a hot day in August so we ended up leaving the windows open which meant it was pretty noisy until about 3am but on a cooler day you would probably be OK.
Breakfast is very basic, not much choice and no cooked stuff but you could easily find breakfast nearby if that was important. There is a nespresso machine so at least the coffee was OK.
For what we paid I thought it was good value for money for the location, we used to walk through Kensington Gardens and Hyde Park and be on Picadilly with only having walked on streets for a hundred meters or so. If you want more comfort then you probably need to up your budget a bit.