We, Poles, complain even more than Czechs therefore I must say staying at Marketa's place was really difficult for us as there was literally nothing to complain about :/
The place was incredibly tidy (we felt safe even during pandemic), the location is really good as Karlín is a hidden gem of Prague and there's a tunnel under Vitkov Hill around the corner so you can get to Žižkov in like 5 minutes and discover the real Prague, not roamed with tourists (the city center is also quite close, roughly 15 minutes away on foot and just a few with subway/tram).
There's a big supermarket (Albert) literally next to the flat and we discovered two very good restaurants nearby:
1. Lokál Hamburk (try the classic Czech Pork and cabbage goulash with bread dumplings and fried cheese), it's also a great place to have a beer.
2. Ngô restaurant (amazing and cheap asian food, tried BÚN BÒ NAM BỘ and MANGO PLEASURE with rice & chicken and for the price of just under 15 EUR for two we were really impressed).
Both of them offer takeaways so it's a great choice if you want to travel responsibly during COVID.
More about the flat - checking-in and checking-out was a breeze, Marketa replied swiftly to our questions, also it is important to note there's a private parking place so if you arrive by a car it's a huge plus as it's really hard to park anywhere in Prague. Driving to Marketa's place wasn't that bad as it's not in the old town so even if you're not an experienced driver you should be able to pull this off :)
The kitchen had everything we dreamed of, the bed was comfy, wardrobe was way too big for just the two of us, you could possibly fit 6 months of clothes in there.
All in all, one of the best stays ever, one of the nicest hosts ever in one of the best cities ever. We were really worried before coming as we're really serious about current world situation and traveling today seems careless but here you have self check-in/self check-out, hand sanitizer provided, takeaway restaurants at your door, can arrive by a car and don't need to use the trams/subway as Prague is very walkable.
It was a great choice after all and we would love to be back one day!