You liked it. It is nearby. It will be a very nice environment for the staff as well as the residents so please don't be put off by one person's opinion.
Also as the places are going quickly you may need to act fast.
Of course there are always going to be nagging doubts but if you liked what you saw, then go for it.
Did you meet the, I was going to say matron, but whoever runs it? If you also get a good feeling about that person, you can be confident that it's going to be alright.
When my friend was choosing for her DH in much the same situation, she went with a retired social worker friend and together that visited 3 or 4 places. One was ruled out because DH was being treated like an object. The manager only wanted to discuss costs and rules!!
In the end they chose a nearby one with mixed reports but something which impressed her was there had been hardly any staff turnover since it opened about 20 years ago. I visited a couple of times and found her DH in the common room looking happy to see us. I don't think he knew us.
I hope whatever decision you make, will be the right one.