We have Winston Grammar as well, but have not really used it much. I purchased it last year and it was too confusing for my then 7 year old and too basic for my then 10 year old. It does help reinforce things though and I plan on using it this summer to keep things “fresh in mind”.
I have also tried Rod & Staff this year with my 6th grader, and we both hated it. It was too much work for him as well as too confusing. He has ADHD so a “busy page” with words can cause him to become confused and overwhelmed. I found myself getting confused and frustrated too
We switched to Easy Grammar 6 and so far so good. He likes the short lessons and the lack of having to rewrite every little thing. In conjunction with that, we are using WordSmith Apprentice to work in our writing skill as well as journaling/copywork.
For my 3rd grader, we are using Rod and Staff but I am not really pushing through it like it should be. She is still grasping these concepts and the book does not give much practice. I am not that worried about it either since I plan on schooling year round. In Texas, we have to teach grammar so there you go. 
Next year, I am considering using Easy Grammar again for my soon to be 7th grader or maybe Analytical Grammar. A friend of mine tried using AG and her daughter HATED it so I may be able to purchase it at a low price…that is should I opt for it.
I also have Serl’s Intermediate Language Lessons for my upcoming 4th grader. I found ILL at a bookstore for about $6 and the teacher guide free online. Of note, you can also find ILL free for an e-reader. I just like the feel of a book sometimes when teaching my children.
The Logic of English turned me off just by price alone. I did not research it though…so it may work for somoene. I am just truly trying to budget like crazy this year given gas prices, etc.