Hotel

I suggest that you post this under "Spain" in the "Destination Q&A" category (left side of the forum homepage). This board is for reviews of places that people have stayed or eaten in. You might look here for people's opinions of hotels where they've stayed, but many people who don't post reviews would probably have recommendations if you ask in the right place.

Also, "not too much of a high end" will mean different things to different people. Sharing your approximate per-night budget, upper limits maybe, will help people help you. If your plans have reached the point where you're interested in particular neighborhoods, or being near a station or particular area, you might share that info also.

Budget-level hotels in major Spanish cities have some characteristics that many Americans find challenging. Fortunately, they do not bother me; I'm all about saving money. Be sure to look at lots of photos on a site like booking.com and read all the English-language reviews to be sure you will not be bothered by whatever quirks may exist in the hotel you are considering. In my experience, the major ones are: really, really tiny rooms; small bathrooms (though the smallest shower was still a bit larger than the many phonebooths I dealt with in Italy); and just one small window overlooking an air shaft (though this often means you get little street noise).

Another issue, not unique to budget hotels, is that dinner is eaten very late in Spain. People will be coming back to the hotel after dinner at midnight or later. They will not necessarily be quiet. This can be an issue if you do not adapt to the local schedule. I heartily recommend earplugs. Good earplugs.

With the above caveats, I will reveal that I stayed at the Hotel Catalunya for ten days last August and would stay there again. It is on Carrer de Santa Anna, a street that is just one block from Pl. Catalunya, a very convenient location. It's a pedestrian street with quite a bit of foot traffic, but I heard no external noise (see above, re: window opening onto airshaft). HOWEVER, they do like to convert your bill to US dollars, using a conversion rate that is good for them, not for you, so tell them you want to be billed in dollars when you arrive and complete the check-out procedures on your last night so you can straighten things out if they have ignored your request (which I suspect will be the case).

Thank you to all that have replied to my query.