Over the 13 years I've been on lawnsite, I have come to realize that the majority of LCOs here just do a fairly basic service. Mow, Blow, Go and maybe a little more. There aren't too many who do the full service you're mentioning. That's why not too many replies to this thread so far.
But you're on the right track, IMO. Going full service is where it's at, if you live in an area where people can afford it. Most people in the neighborhoods we service have a landscape maintenance company (as opposed to doing the yard care themselves). Many of them have some sort of version of full-service. It's sort of expected around here. I think if you went around just offering a mow-blow-go service in the neighborhoods we work in you wouldn't get much business. You'd just get the pikers, late payers, cheapskates and price shoppers only. That's the clientele I USED to have, about 16 years ago when I first started, because I didn't know any better. But after a few years I wised up and finally realized that we could make a lot more per account per month if we would just offer a more comprehensive service.
We offer a bronze, silver, and gold service. But even the bronze service offers a lot more than just your standard mow-blow-go. You can read more about each service and what's included on our website. We only get about 5-10% of the people who chose bronze. About 70% choose Gold and around 20-25 choose Silver, which is basically full service except not pruning of shrubs and trees.
I think the best approach is to offer several service options like this. This way, you're not FORCING anyone into a more comprehensive service. You're just allowing them to choose. I find, in our area, most people CHOOSE the most comprehensive service, but your mileage may vary.
As for add'l cost, it really doesn't take a whole lot more time per week to make sure weeds are taken care of, leaves are removed, grass is fertilized, perennials are trimmed back, etc. It's easy just to spend 10-15 minutes more each week just working on one or two of these items, outside the lawn. Then the next week you work on another. And so forth. Just a little extra time each week. But it will allow you to charge anywhere from 20-50% more, depending on the property. Properties with larger trees that drop tons of leaves in fall obviously pay a lot more than a property with only a few 8' ornamental trees. Etc.
Hope that helps a little.