Catherine,
Thanks for asking your question to planDisney!
NO! It is not going to be odd for you and your husband to stay at 
Disney's Pop Century Resort without kids! I stay solo at Pop Century on most of my planDisney reunion trips and will be doing so again this fall! 
Pop Century is such a great location. You are a 
Disney Skyliner ride away from two theme parks, the 
Disney's BoardWalk, and some fun resort hopping! On an adult-only trip, where you may not be doing much at your resort hotel other than sleeping & storing your souvenirs, it is a super place to stay. You get a vibrant, fun, well-themed resort setting while keeping your costs down. 
When I am given the choice of a room at Pop Century versus a larger room at a non-Disney resort with perhaps more in-hotel amenities for the same price, I always pick Pop. 
Why? Transportation times to the parks are shorter, and I never leave the magic during my stay. It is an easy decision to make. 
Please 
write me back if you need more Pop Century pointers. I always love to chat about one of my favorite places!
Have a Magical Vacation!
Doug