Okay some update on this. This evening or tomorrow we have new build that has some changes (and at least one fix) that might affect the issue people report. However, there is also part of this problem where we feel users do not fully understand the systems. We spoken extensively with busdrivers to understand this better.
For starters we feel part of the users underestimate what standard vertical speed is. Now there are some minor differences between airlines but all pilots agreed that 3000 fpm is perfect, anything under 5000 fpm is nothing to be worried about that are even higher descent rates are not all all abnormal.
The second issue that plays a part is that the busses tend to dive pretty steeply to catch the profile, certainly very pronounced at higher levels. This is a very normal effect, though not welcome. If all is perfect (wind etc) you might go from level to the standard 3000 fpm without issues, but all the pilots we spoke to would normally use VS at the start of the descent. In many airlines this is even advised procedure. This gives the system more time time to settle on a good profile, get rid of some speed where needed etc. Also the use some spoiler might be needed in certain conditions (real pilots seem to use them a lot more then simpilots). This might explain why for some of the discussion we did not see anything special while the customer saw something he/she did not expect.
The reported vertical speeds of 6000 fpm 'could' in fact be 'normal' (but of course highly undesirable). If you get to ToD with high speed and some serious winds from behind you have way too much energy to allow for a sweet entry to the descent path. The FMGS would do all it can to stay on the path. It's up to the pilot to avoid that and to correct it.
Another 'trick' is to start a slight descent before ToD and then use managed descent from the TOD, they can push the altitude when they are below profile and this will set a 1000 fpm descent until the profile is intercepted and then it will be a more comfortable capture and will stabilize on profile much more smoothly.
However it seems that these occurrences seem to occur far too often for some users and when it happens it seems to lead to unrealistic values to soon for some users. For these people the new file might very well change things.