Planners were never any use to me...When I got one I would always use it faithfully-------for the first day or two....After that it was pointless because in order for the thing to be useful to me, I would have to REMEMBER to write what I needed to write in it....or REMEMBER the fact that I had the durn thing in the first place and to refer back to it, or more frequently, I would just end up loosing it anyway....so it was really no use..a waste of money to me.
Now OUTLOOK is better....I get notes popping up in my face when I forget....now THAT'S what I need..something to POP UP IN MY EYE to remind me.....otherwise, you can pretty much forget it..
I know exactly what you mean about love/hate with your planner. I even made one for myself out of a small binder and homemade divider tabs so I could have exactly what I wanted in it and laid out exactly how I wanted it. That's worked really well, but I have it laid out so many different ways- full month calendar for really important stuff, weekly with room for notes, appointments, due dates, etc. That's worked really well so I know what is coming up so I can work on things in advance (or just stress about them and do nothing) and not forget appointments. I really like to use the calendar on outlook because of the reminders and how easy it is to move things around when something changes, I can color code things, and I can see on the grid how much time things take out of my whole day (I really love outlook!) but that only works when I'm by the computer which is usually not much because I'm a college student. I really really REALLY want a PDA but I don't have the money for one.
I have more trouble with each day by itself. I plan out every day on a separate piece of paper with my to-do list next to it so I know what needs to fit in there then I cram it all into a schedule, but I never stick to it because I HATE schedules and structure. I don't have any advice for you, but if anyone else does I would love to hear it. I think my problem is that I plan for what I think I should be able to do, but then my brain gets tired.
By the time I have planned a day of activities and tasks I'm too tired to do any of it, so I just go surf the net or watch tv instead.
I've got an A5 sized diary with 1 day to a page and with the hours of the day down the side. It's the size of a thick novel but I carry it everywhere now. Writing a task down is not enough, but writing what time I have to do the task at seems to help. I feel bad if I don't tick off anything all day.
Writing the next day's activities before I go to bed can be useful, then I jump out of bed with a better idea of what I'm going to achieve in the day.
I told my shrink I always felt bad when I had wasted the whole day doing nothing. If I actually write a to do list I sometimes only do 1 out of the 10 things.
He said I should write the to do list at the end of the day not the beginning and that way I'll always feel happy because I'll can just write down what I did that day and pretend that is what I had planned to do. 
So my to do list today is watch a dvd, cook a cake, read a magazine, go to the shops, email some people. Not very productive, or what I should have been doing, but at least I feel like the day was a success!