I've read from posters here that you should stick with a given program for at least a year.
On the other hand, I've also read that all good programs follow the same basic principles, and as long as you eat and recover you can progress, regardless of your program (provided it isn't something stupid).
Now, I understand that program hopping every 3 weeks will leave you spinning your wheels, but what about every 3 or 4 months?
Does it really matter?
Is 12 months of HCT-12 going to be more beneficial than 4 months of HCT-12, 4 months of BGB, 4 months of 5/3/1, provided all other variables are the same?
If you stick with the routine then your intensity stays high and you keep progressing with new PRs. If you switch the routine you'll have some down time while you build the intensity back up and start hitting new PR territory. Wasted time if you don't need it. And like you said, if the routine is similar, then there is no reason to switch if you are just going to have to gain back the ground you lost.