We use/used LLTL this year. Level 3 for my DD (3rd grade) and Level 1 for my ODS (1st grade). I like but not 100% on it either.
Level 3, the grammar taught, is really good but it was not clicking for my DD. She likes to diagram, which I think helps her “see” what she is doing, but she needed a lot if “hand holding”. Maybe I should have done level 2. I am using Spelling Wisdom for copy work and dictation so really I was using LLTL for just grammar and reading suggestions. I am sure I was not using to full potential, and as I said, maybe level 3 was too big a jump (she did R&S grade 2 English in 2nd grade).
I really like the book selections in level 3, but what we ended up doing is using the reading schedule but I switched to PLL (using the PDF printable work book available). Some of the lessons like dictation or memorization we skip, but it is inexpensive so I do not mind. We have to do Stand. Test this year so I wanted to make sure she gets the basics of grammar, so I tried out KISS grammar. It is free, I just printed the work book. I liked that I could just print some sections like punctuation (which she did not really get any of in LLTL) or noun/verb work. I am not overly worried about testing, but do not want her totaly “lost” either 🙂
Next year I think I am going to have her do ILL and KISS Grammar, add in starting written narrations for writing (which ILL does too) and I think it will work for LA umbrella. KISS is a bit funky to figure out at first, not all grade levels are available in free workbooks but I think I figured it out, LOL).
As for level 1 LLTL it is very nice and gentle. It has been just right for my ODS in 1st grade.