If you had a choice between a used Classen TS-20 and a Bluebird S22 which would you choose and why? The design of the Classen seems more intuative to good seed to soil contact, but maybe the folks at bluebird know something I don't. Both units are in good shape and are selling for about the same price. My purpose for the unit is mainly for overseeding after landscape/hardscape installs but I'd like it to be a multipurpose unit for dethatching/power raking for those times when I need it (spring cleanups could use a power rake sometimes). Both mfg claim that can be easily converted for raking/de-thatching. Are those claims acurate is it just window-dressing?