hey man i did about 3 or 4 months of straight HIT a little while back.
it was awesome, but it had some adverse effects. I am not gonna say I got smaller, but i definitely got weaker when returning to regular training with conventional reps and sets. My squats, deadlifts, and bench all went down drastically, and I had to work hard to build them back up. Maybe my experience was unique, but my training partner who joined me on this HIT experiment had the same problems of getting weaker.
All in all HIT has its advantages, and despite getting weaker, I still enjoy doing it maybe once or twice out of the year for a few weeks.
Have you ever tried regular training to switch things up? Do you notice any difference in your strength?