i few changes id make if I still used my sunbeam: replace the aluminium portafilter (complete with a weight in the handle to make it feel heavy) with the brass/chrome one that comes on the 4800.
and I still think the major design flaw is in the materials used in the grouphead - the part that you lock the portafilter into. Its ABS plastic and fairly strong, but it will bend over time, with excessinve pressure buildup such as is necessary for lovely sunbeam ristrettos. Krups use the same design, same portafilters, same baskets, but the part is metal, not plastic, and Im guessing less prone to bending out of shape under stress.
I cant pull a shot on my sunbeam anymore without having to hold the portafilter in (that said, its been a good 8 months since it was even turned on) during the shot.