We are still in our first year of doing Sonlight. I got it when I was so stressed out about homeschooling, and since we happened to get a bonus at DH's work, we were able to purchase 3 Sonlight Cores (our children are at quite different ages and abilities... I didn't want to be tweaking so much to make one Core work for everyone). It has been a 'lifesaver' for me... we've gotten back on track and I've really felt we've learned a lot more History this year than ever. The literature has been great... they choose good books that I feel support the moral and intellectual growth of my children. No twaddle, as Charlotte Mason would say. BUT I have 3 children that are really doing schoolwork (plus a couple preschoolers that I just make a point to 'teach' informally), and keeping up with 3 Cores, although do-able and enjoyable (I love reading to them), didn't leave ANY time left for other things like foreign language, music, art, or enough outdoor time (or housework). After continuing through my first trimester, I was feeling a little burned out trying to keep up with the schedule (and not feel behind). I had set a goal to carry on through the summer (we never break more than a month or so in the summer anyways) because the number of weeks left in the Cores was 2 weeks less than the number of weeks left in my pregnancy, but I ended up taking about a 7 week break.
Then I discovered Charlotte Mason and it really suits my style and philosophies about education. Also, I don't think we can afford to get three (or four) more Cores when we are through with these. But I do have a great home library of literature and historical fiction and texts like Saxon, and Apologia, and Story of the World (SO many I've picked up for very little cost at booksales). We are enjoying the literature from the Sonlight Cores, so I plugged all the Sonlight books and assignments they have left into the SCM scheduler... and we are continuing without the stress of the deadlines. We just get as much done as we can by about 2 or 3pm (we don't get started until about 10am) and when life happens, that's just life... next day we start where we left off.
Since all my planning is done for now, I'm now looking ahead. Before #8 arrives, I want to have next year all planned a la Charlotte Mason style. The SCM planning book makes it seem so straightforward and simple. When we are done with these Cores, then I'm going to combine a lot of their subjects to save myself some time so that we can add in the other things we've been missing. In the meantime, we are gradually incorporating more and more Charlotte Mason, like I've started a little with oral narration. Also, for the 7yo in particular, I make sure that he has a little reading, then a little writing, then some time listening to me read, and so on, varying the types of activities and I find we get through his schoolwork easier that way now.
Long post, but my point is I think SL is great in a lot of ways. If I would choose any boxed curriculum, it would be Sonlight hands down. (We've done a lot of Abeka in past years as well). But with my larger family and financial considerations, I won't be using it next year. (I'll still keep a catalogue though for reference). I'm excited about next year and I'm going to go to a Charlotte Mason group for a while and I'm going to slowly get my homeschool closer and closer to Charlotte Mason ideals.
God called me to homeschool my kids, I'm sure of this. And He will make it work... even though in my own eyes I'm organizationally challenged and only a mediocre mom. I'm learning to trust Him more and more to lead our homeschool, instead of always feeling like I'm inadequate and searching for the 'curriculum' answer to the perfect homeschool for my kids.
So I guess the answer to your question is to ask God to show you the answers you need. Look at the resources God has provided you with (I wouldn't go into debt to use a boxed curriculum, for example). And try not to worry too much.... keep at it... doing some everyday, even if it doesn't always seem like enough, and your kids'll keep making progress. If they miss a certain period of history or don't learn much about a particular science discipline... they are still going to do JUST FINE. If you can find a way to make your homeschool life a little easier for a while (concentrate on only a few subjects that they can do more independently for a while, like individual reading, penmanship, math workbooks/texts) while you take the time to prepare some homeschooling plans and 'regroup', that might be helpful and give you time to think about your goals and make a plan... having a plan is a real lifesaver. That's one of the things I love about Sonlight... it's planned out... and I'm sure that's one of the things people love about the SCM as well.
My first years of homeschooling were a bit hit and miss to say the least. (NO plan). They got phonics, printing, grammar (Abeka), I read to them lots (quite a bit of historical fiction but all out of order), we've always done well with Math, but they hardly had to write anything (besides penmanship workbooks), and other subjects were either just touched on or practically neglected. Now I have an 18 year old who knows she wants to be a paramedic so she is taking a couple of Grade 12 science courses at the local highschool to get the final credits she needs (she did a couple online courses last year at home)... and she is doing VERY WELL. She has her NLS(Lifeguard) and Swim Instructor's qualifications and has started a job at the local rec centre with that. I can see now that she is going to do just fine... but I worried a lot over the years unnecessarily.