Is one area preferable over the other in terms of location, proximity to public transport, ambience, etc? Thanks in advance.

There is another thread going with this question. I think P.Navona/Pantheon area is preferable because it is more central to a range of sites you will want to see. The Spanish Steps area is more convenient or shopping at the high end stores. It is also next to the metro, but the metro only goes to certain sites at the edge of the central historic district. P.Navona/P della Rotunda are convenient to many bus and tram routes.

Public transport is good in Rome so that would not be an issue.

Insofar as ambiance, IMO it is how you define it. We have learned that we prefer to be out of the overcrowded tourist areas, after years of staying primarily near the Pantheon. Now we stay near the Borghese Gardens and Via Veneto for a quieter experience, fewer hordes of tourists and some more interesting dining options.

We love to walk and find the area very convenient.

This is the other thread comparing the two areas
http://www.fodors.com/community/euro...-di-spagna.cfm

It's very hard, and depends what your priorities in Rome are. Is it budget, transport access, pedestrian access, partying, history, fashion, dining?

As for general life I would recommend the Pantheon since many things are open later than near the Spanish Steps and the Spanish Steps are mostly boutiques anyway. But the Spanish Steps are definitely more metro accessible.

As far as walking and staying outside of tourist areas, both Parioli/ the Borghese area and Trastevere are really great options....but remember, it depends what YOU want out of Rome!

Although it's a bit pricier now than when we stayed here a few years ago, we loved the Hotel Barocco on Piazza Barberini. Based on their website photos, it looks like it's been renovated since then!

It's walking distance to shopping, the Spanish Steps, Fontana de Trevi, etc. etc. Enjoy!

www.hotelbarocco.com

I've loved staying adjacent to the Pantheon at Albergo del Senato, and I also enjoyed a quiet stay in Trastevere my last trip. When we stayed near the Spanish Steps it actually did not suit us as well, but as others have said it depends on what you are wanting out of your stay.