What else is there to say about the "home stretch"? The views from the top of the climb around Ponte Ulla and Outeiro are nice (but you already passed those before Lestedo). I didn't know about the Pico Sacro ...
Your opportunities for filling the credencial with its final stamps are the Bar Rosende next to the Reina de Lupa albergue (a couple of hundred meters off the camino). Very friendly, but I doubt you'll need a break at this point. The next bar is only a short distance up the road in A Susana. And then, according to Gronze, after you pass the little chapel (Emita de Santa Lucia) there's another bar in Piñiero, but I don't have any memory of it. Somewhere around here you'll catch your first glimpse of the Cathedral spires. Hard to remember the details at this point, I must always be single-mindedly focused on getting there.
I'm told that these last kilometers on the Sanabres are more pleasant than the way into Santiago on the
Camino Frances. There are a couple of road sections, some muddy, grassy bits, one or two pretty little stretches, like the bit where you walk under a canopy of vines between two farm houses, some highways and high voltage electricity cables to pass under, and the railway bridge / crash site that Peregrina2000 mentioned. To get over the railway bridge, you've got a short, irritating, climb - Not a proper climb up a mountain or anything that you might actually want to do, just a last-minute "fooled ya!" kind of climb. After the bridge, you'll get your reward, though. From there on, it's a descent along pretty, old-fashioned streets, until you reach the pedestrianized old town.
Overall, I think it's not an especially beautiful stage until you're in the old town of Santiago itself (and that's very beautiful). But it's not bad. It's a fitting end to the Camino. Compared with entering Ourense or leaving Granada or Salamanca, it's bliss.
Albergue Seminario Menor looks great. I think I'd treat myself to a private room if I were to stay there. I stayed at The Last Stamp albergue last year and found myself with some pretty feckin' ignorant room mates. I don't mind that they'd never heard of Poland, but by the time you reach Santiago you ought to know better than to make a long phone call from your bunk in the middle of the night. The Last Stamp had jacked up its prices since 2017, when I spent one night there. Back then, it seemed like a good value. Now, I'm not so sure.
Come to think of it, my room mates there in 2017 were kind of boorish too - three cyclists from Portugal who hung their gear out to dry across every square centimeter of the shared space, and made a huge racket when they left very early the next morning. I think it's just a shock to my system to find myself in Pilgrim central after being on a less popular route. The camaraderie and feeling of fellowship is diminished and I find my defenses going up. Some things seem so dog-eat-dog. I find people making a sudden dash to position themselves ahead of me in the queue at the pilgrims office. A woman accuses me of having one of her socks in the dryer with my clothes. (Yes, of course, I'll check when I remove my things. No, I'm not just going to walk off with one of your socks. Yes, of course, it's fine for you to stay here and watch me to make sure of that. And how was your Camino?)
In Santiago, I've also stayed at the Compostela hotel on the Plaza de Galicia, which is modern, comfortable, and super-convenient for the airport bus. I've also rented an entire Airbnb with a couple of other pilgrims just off the cathedral square, which was pretty awesome. I must try the Seminario Menor and the Parador one day.
Things to do in Santiago - You probably have your own preferences. I was thrilled to be able to join the guided tour of the Portico de Gloria last year. Tickets are offered to a select few pilgrims who collect their credencials at the Pilgrim Office (who knows how that will work in the COVID aftermath). I'm a huge fan of the museum of the Galician people. The building and the exhibits are simply fantastic. The answers to all of the questions that you asked when you were passing through Galicia are all to be found in the museum. As well as color coded maps for festivals, architectural styles, agriculture, and other cultural phenomena, there are some fascinating isogloss maps of Galicia. (Yes, your ears weren't lying, the Galician language in some of the regions that you walked through sounds quite close to Portuguese). I also like the museum of pilgrimage and the cathedral museum. In all of these places, it pays to have your credencial with you to qualify for the generous pilgrim discounts.
If there's time after all of that, I would recommend a quick visit to the Mercado de Abastos for some foodie souvenirs, followed by a lazy afternoon of sampling Spanish wines with ham rolls at Casa Pepe. And if you need a beard trim or shave, I recommend Barbanosa at 1 Rúa da República Arxentina.