Bro, Grace "Sedan" category mein aati hai, whereas "Aqua" is a hatchback.
Being Sedan; Grace ki suspension achi hai, however, Aqua has better resale, its a bit rough and tough being Toyota Badge, has better market value, fuel efficiency, easy and cheap availability of parts as well as spares (although spares are a bit expensive, but are available at least), maintenance is a bit cheap and easy (mechanics ko ub isski kuj na kuj samajh aani shuru ho hi gyi hai). Grace mein aapko ye sub Aqua walay pros nai milein gey.
Being market ki gari, if I had to choose between these 02, I would definitely go for Aqua. Rest, all depends on you; your budget, needs and requirements, and ultimate choice will be yours.
I hope, it helps. Thank you.