I have a large X-10 system that I installed decades ago. ………………………..
..............Are there any other boxes with a great computer GUI that will work with X-10? If so, which is the best?
The X10 forums no longer attracts the viewership it did back-in-the-day. These days.... there are only a handful of us regulars.
And I am sure all of us have read each of your several posts. Your options are NOT limited. But you'll need to decide and express what kind if direction you wish to go.
Are you looking to just replace what you already have and know?
Do you wish to invest a little learning time and money to upgrade?
The changes in Home Automation since you chose X10 back in the early days..... has been
staggeringly enormous. Maybe... instead of searching keywords and posting (and reposting) to old threads.... you may want to take a little time and read some current posts.
By the way......
welcome to the X10 forums!