The reason to book this cottage (besides how cute it is from the outside) is its location. It is right in the middle of the action, and everything in Galway city center is easily accessible by foot. Parking isn't too difficult to handle, either. There are plenty of on-street spots nearby.
Being an old cottage, it is quite tight inside, and the ceilings are low. I am 6'2" and had to duck in several places. But it's a comfortable place. Ideally, you won't really be spending much time here anyways. If you do plan to spend a lot of time at your Airbnb, you may want to get a place with a bit more room to spread out, especially if there are more than one or two of you.
So here are the downsides: the cottage is right on a busy street and backs up to some bars, so it gets VERY noisy at the weekends. If you have earplugs, this shouldn't be a problem. But my friends had a lot of trouble sleeping. For some of you, you sleep like a rock and won't have issues, or will do fine with a white noise app or something. But I couldn't imagine falling asleep on a Saturday night without earplugs.
Also, the cottage is definitely cuter on the outside than on the inside. It's pretty sparsely decorated and feels a bit neglected, to be honest. It could do with a fresh coat of paint and some TLC. It wouldn't take much to make it really inviting and beautiful inside. Again, you may not care about this. It didn't really bother me, since we were out and about all the time. But for those of you with more of an aesthetic bent, you may find the contrast between the outside and inside quite jarring.
All in all, I'm happy with our stay in this cottage. Galway is a pleasant, walkable city, and this cottage makes you feel a part of the city's pulsing life. The nearby pubs and restaurants we went to felt like genuine neighborhood places. We weren't surrounded by fellow Americans like on so many other parts of our trip, which was refreshing. This cottage is good value, comfortable, and functional. I can recommend it with the caveats mentioned above.