SoftWave, Stemwave... what shock wave device would you buy for your office?

Hi guys, I'm thinking about purchasing the stem wave because it is $50,000 compared to the soft Wave which is $80,000. The maintenance for the stem wave is like $300 for a new shock plug compared to the soft wave which is $3500 it seems that the fees charge are basically the same which are $150-$300 per visit. Have any of you purchased a soft wave or stem wave or the cheaper version the Chattanooga thanks