Well, it depends what this fellow and you have as priorities.
Basel is certainly not a big city and the native language is German - although you will hear a lot of English and French spoken, the official language remains German and if you catch someone on a bad day, they will remind you of this.
That said, as mentioned by FabrizioM, the people in Basel are relatively liberal and open minded compared to much of the rest of CH.
Location wise, it is nice and central to Europe. It is not so central to Switzerland though, and getting to the mountains (if that is of interest to you) takes longer than say Zurich, Zug, Bern or Geneva.
Weather-wise, AFAIK, the weather in Basel is usually sunnier and 1-2° C hotter than the rest of CH due to a ring of mountains/hills that surround Basel and keep the climate fairly warm and stable.
As mentioned, it is not a big city. But culturally, Basel does punch above its weight and has many diverse activities in the arts, with over 30 odd museums within a few hours distance. It has a concert scene with diverse performances, and it on what I term the "international" circuit. What isn't here, will certainly be in Zurich and that is only 50 minutes train ride away - most people take longer to cross cities.
What it doesn't have is lots of the same type of thing. So there won't be 10 theatre different productions/shows, or 10 classical concerts on the same night. Rather you'll have 5 concerts, including a Jazz one, a couple of classical, rock, pop etc.
Access to all areas is great and public transport really top notch, which means you are rarely stranded anywhere if you choose the right place to live (i.e. don't stray too far away from public transport options).
Enjoy your trip and hope you find what you are looking for.