I am stunned by your negative experience with the Xtool PreBanMan! I do think you must have just gotten a rare bad lemmon or have some other ancillary problem.
Our shop has more than 12 scanners, and while some are fairly basic, and others have been a nice suprise, the D8 is just outstanding! It has become our go to device in the shop.
Our inbox is full of quick and helpful responses from DirectXtool (an authorized dealer who sells on Amazon as well).
In one case, we had a need to program a key on a vehicle that the device did not yet have an update for. When I emailed DirectXtool, they sent me back an email within a few hours and offered a beta upload to address our problem. This device covers all brands, and they said the udate they sent me was not scheduled for release for another 40 days. But they saw our need, and helped. Who does that?! I have never had that kind of support from any of the other tool manufactures.
I have got to admit I was a little concerned about buying such an inexpensive scanner. 700 bucks seemed just too good to be true for a scanner that needs to perform at the level our shop requires, and I advocated against it in our budget meetings. But after putting this thing through its paces on the shop floor, I am amazed!
Another thing that really makes us convinced your experience was an anomaly PreBanMan is your experience with slow results. My gosh man, this thing just blazes! In fact I had to be shown several real time YouTube videos (Yep YouTube again

, before I relaxed my position on its purchase, since we have all had that experience of slow scanners you speak of PreBanMan, it was one of my primary concernes. Yet one thing we noticed was that nearly every owner and reviewer that post anything on this device remarkes about its speed. You are the first and only one we have ever come across that has experienced this issue.
I can't help but wonder, Did you buy the thing from a non authorized dealer? One of the post I read out there did, and warned against it. But they did say that when they asked DirectXtool for support they still graciously responded with support.
One of the reasons almost all of us wind up with multiple scanners is that some seem to excel in one area but not others. We have not really found this units weakness yet, but we will share anything we do find. At last weeks budget meeting, we agreed to buy a couple more. There is too much competition among the mechanics for the dumb thing, and our road mechanic seems to like to take it with him on his calls, which causes some hard feelings. I personally like him to take the less expensive unit, and leave the higher dollar ones in the shop.
By having a few D8's to compare side by side, our odds of finding any shortcommings, or inconsistencies between units will go up. If we do get a unit that acts up or shows any of the attributes you saw PreBanMan, we will come back and share on this forum.
But for now I am just astounded at your experience. Good luck brother.