I have a watch collection mixed with G-Shocks, Seiko and Citizens, and some nice Swiss pieces from Tag Heuer, Omega, and Doxa. I originally bought the Space Grey Sport which that cash would had went towards a G-Shock. When Apple released the Space Black on Sport band which went on sale for the Best Buy $100 off deal around the holidays, I sold the Space Grey and upgraded which is usually how my watch collection works, 1 in 1 out. I then purchased the Link bracelet off Ebay which ultimately this whole sale would had went towards a Citizen Signature Automatic.
I will add, since I got the Apple Watch in Space Black, my watch rotation has stopped rotating. This watch rarely leaves my wrist except when doing work around the house or going out with my wife. It now has me seriously considering reducing the size of the collection.