Depends on how into one wants to go - you can do a low light/low maintenance planted tank easily with no extra work or trouble at all - it's only when you start delving into the higher light/nutrient needy plants that it becomes a hassle with having to add light, add CO2, etc. Our two planted tanks require no different care than the two non-planted because I have low light plants that don't require CO2 injection and all that jazz.
That was just the issue. The plants were an impulse buy from a fish store, and they were high light co2 requiring plants. I can't remember names, but they were very fine leafed plants. They all died of within 2 weeks. Now, if I want plants I just have Anubis.