Honeywell L7224U electronic aquastat

Is the L7224U electronic aquastat a reliable piece of equipment at this point in time?
Is appears to have a sensor probe on wires. What would keep the end of the sensor firmly positioned in the well? I assume it needs to be firmly against the end of the well.
We need to replace an 11 year old conventional L8148A and hope that this might be a solution to the very loud rattling buzz that we've put up with for years.

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