Paddington Station Accommodations by Premier Inn

Mostly size of rooms.
I travel solo and Hub is fine for me. Some people, especially 2 in a room, might feel cramped.

The Hub rooms are smaller than the regular rooms at Premier Inns. If you're going by yourself, you should be fine, and even two people would probably be okay; albeit a bit cramped. Keep in mind that some Hub rooms do not have windows.

The hub at Paddington Station and the regular Premier Inn are located in the same building. The Hub rooms are on the lower levels, and the regular are on the higher levels.

Have you checked prices at the Premier Inn Paddington Basin? That's another Premier Inn that's located near Paddington Station. So you might want to check all three for prices.

I don't think the Hubs have amenities like a kettle for coffee/tea in the room. They do have rooms with king beds (called "bigger" rooms). Also, nowhere to sit but the bed, maybe no closet, either.
Lots of posts on the forum about budget accommodation in London. I just did a quick comparison between the Hub and the Darlington Hyde Park, which is just a couple blocks away, and Darlington was 424GBP for a single room (probably a small bed, didn't look closely) vs. the Hub's 495GBP. Breakfast is included (and not bad) at Darlington.

Fjord, when are you going? And how many nights are you staying?

Hubs do have other places to sit than the bed, mine had a chair and there was a place to hang up clothes (not a closet, necessarily). Do consider carefully how you may like sleeping in a windowless room. My windowless basement room didn't bother me until I was ready to sleep, then it felt extremely claustrophobic. But I did enjoy the room layout/set up and survived my 3 nights, but I won't be staying at a Hub again.