The MEGA features is the best on the market. HB's customer service is second to none. The HB is easier to set and use and features 3 presets buttons that Garmin does not. Garmin pirated SI and DI from Lowrance, Lowrance stole it from HB.
Garmin uses 55/70/200kHz which are a bit unusual. HB uses the industry standard 63/200 kHz.
I have used and taught both. Users seem to prefer HB, so do I.
Capt. Craig Copeland
Licensed by the US Coast Guard
2013 Nautic Star 2110 Shallow Bay Boat
Humminbird HELIX 12 CHIRP MEGA SI GPS G2N
Nautic Star Boats Pro Staff (nauticstarboats.com)
Redneck Fish'n Jigs Pro Staff (redneckfishn.com)