I was not sure what you meant by your antenna performance not being up to it but I usually just use omni antennas and they work fine for most LEO sats.
I haven't yet worked a linear satellite successfully. It's not so much the automatic tuning that's getting me down as much as it is the desensing/crosstalk between the 2m and 440. I chalk that up right now to the fact that my antenna is a 2m/440 combination which I plan to switch out with two seperate antennas as soon as I get around to it.
The tuning in my application is essentially a control which allows you to tune within the passband of a linear satellite both on the uplink and downlink with a single 'knob' also taking into account if the satellite is inverting or not. I haven't yet gotten to test its operation in practice, only theory.
Scott NW2S