Both are bang for your buck games, DM is deeper that Getaway, has more modes and multiballs and if you use the handles to play the scoring is higher( cool touch) backglass and artwork are a bit of a bore..both are pretty fast but there are much quicker pins around than these titles.
Getaway is fun but it is a one trick pony and gets boring prety quickly imo.
I prefer DM to Getaway, so that would be my choice.