We have dish drawers that we love and have had them for about 2 years. We bought ours in the paper for $50 because the person that owned them first thought they had stopped working and had bought themselves a new dishwasher. We have had very few issues with them (it has been blocked a couple of times, but nothing DH hasn't been able to fix himself which was the problem with it when we bought it).

As for the insides being plastic (I assume that it is the washing arm), the reason that is is plastic is to stop things that touch it by accident during the wash cycle from melting. Our last dishwasher melted a couple of knife handles and plastic cups because the metal would heat up so much, the plastic is there to stop the melting.

I guess we got a nearly new $1500 dish drawer for $50 so it is a bit hard to complain about the 2 years we have got out of it so far. We thought if it lasted us 6 months we would have got more than our money's worth out of it ... but it is still going strong.