We are planning to visit Shenyang from 21 to 26 October '14.

Yes, there are enough places for travel for five days in the city. You can visit the historical sites such as Imperial Palace, Zhaoling Tomb and Fuling Tomb.
Or you can go to some natural scenic spots, like Glacier Zoological Paradise, Botanical Garden and Strange Slope Scenic Area.

Compared to SY,Beijing has more splendid attractions, such as Forbidden City, Great Wall. So it’s advisable to pay a visit in Beijing if you have another 2 to 3 days.