Ive only had the La San Marco and the VBM. I have a friend with a Saeco Via Venezia.
The LSM was their "home" model, had a brass boiler (about 200ml) and a reasonable portafilter set. My friends Via Venezia was no match for it, even with a non-pressurised portafilter.
From all that I could gather (I am a compulsive comparer!) the LSM was *about* equal to the Silvia, having cost $350 wholesale about 20 years ago.
When it died, and parts were no longer available, I wanted an upgrade as well, having already bought a Rocky grinder. Since I am the only coffee drinker, making many coffees in a row easily didnt count, and I didnt want to spend much over $1000 on a new machine. It ended up as a toss-up between a Silvia with PID or the VBM. In the end it was the history and raving about E61 machines that decided me.
The VBM beats my LSM easily, and makes coffee such that sometimes I just have to have two in a row! It uses more water, takes longer to heat up, and looks great when its clean.
The only coffee Ive had that I enjoyed more was made by Mark Barun (the coffee barun) on his new Synesso machine.
Is it worth it? It is to me. Of course YMMV.