Sounds to me like you are talking about TC East, the airspace between Logan and Lam. A part of the problem here is that unfortunately there are usually quite a few of you pilot chappies about, and the poor guy/gal working on east has to try and give you what is already a tight descent clearance, in airspace which is narrowing, and stream you for Lam in the hope that you won't hold, hence the speed restrictions, not to mention working you around the other inbounds and the overflights. The speed may also be for separation from the one in front and the one behind too!
I'm not suggesting that we couldn't do to learn more about whether what we are asking you is possible or not - of course we all could. Just that they may be doing a particularly tricky task and trying to give lots of planes a good service. In general you all arrive at once, hence the R/T is bad too... we understand. Just keep trying to get your work in edgewise and let them know what they are asking is just not achieveable.
Someone who does the sector may be able to help more (I used to, but don't any more.)
Cheers,
N
"Keep smiling, it makes people wonder what you're up to...."