With the journey from ahmedabad to bombay I always use to prefer shatabdi exp, because I like it as a best train because of few reasons,
it is a day time train which I like the most.
it is super fast train and hardly stops at stations.
it is always on time . ie. its arriving time and departure time is perfect. mostly it arrives early but not late.
its seats are very comfortable. and has good facility for luggage.
no tension to carry any eatables items because it provide it in very well mannered.
more over its interior is very clean and toilets are also well cleaned
hence, one will have a memorable journey with shatabdi exp so, just go for it.