My trip will be just 2 full days & nights in Mumbai, sadly!

The Taj looks awesome but is it almost too huge and too overwhelming for such a short stay or no? I had seen Oberoi, it looks quite nice as well.

And in regards to St. Regis & Four Seasons, which seem right by each other, what would be around them- anything worth seeing or no?

Juhu isnt worth a consideration I assume as its too far?

If I stay down in Colaba as you had suggested will I be able to walk to some of the sights- i.e. Gate of India & Marine Drive.. However, getting to Dhobi Ghat, Juhu, etc then will be a long transport.

I've never hired a professional tour guide as I love to just walk and explore.. However, Mumbai (maybe India in general (seems overwhelming and so big and so much to do. I was thinking mabye for 1 of my 2 days to set up a tour with a local.