"Little Shop of Horrors" is the "Ultimate Musical for People Who Don't Like Musicals" It is untraditional from the ground-up, taking its inspiration from a shoestring-budgeted Roger Corman film, which happened to feature a young Jack Nicholson. It also has a fairly un-Broadway Score, with lots of street-corner doo-wop, my favorite being "Ya Never Know" A close-second is "Dentist"
The scale of Portland Center Stage's version is perfect. Midsize. "Little Shop" is so frequently produced-by small theatres, and even high schools--that one might be fooled into thinking it's a small show, and yet, I also saw the Broadway in Portland Touring Version, in the mammoth Keller Auditorium, where it was swallowed. (I just realized "swallowed" is a delicious unintentional pun!) Also, the medium-ness of the production allows the puppets to tower even more.
Here's my advice:
1. Take a reluctant friend
2. Be ready to laugh
3. Don't feed the plants