My take is yes a lot of what you hear about the HDS 5 is true. I owned one for a brief period and i was 100% not impressed with it. I had a 520c that i was not at all happy with the performance of from a fish finding standpoint. I had been dealing with Lowrance for over a year to get it resolved ( software updates, downgrades, new units etc) to no avail. When the sidecsan was announced i figured i would get somewhat ahead of the curve and i got myself an HDS5. I didnt have any failures per-se but performance was again a problem. For such a simple install( transducer strapped to a tm) to not work as one would expect( i couldnt pick up a bait ball that i could actually see with my eyes or a 5 gal pail i planted in 10' of water) leads me down the road they there is something wrong with the design. The real issue for me and what drove me to make a change was the customer service. I never spoke to Linda but i can tall you the people i did speak to were either aloof, condecending, rude or a combination of the three on the phone and it was obvious they didnt care. I got pretty angry after dealing with it for as long as i did and i still have a bitter taste in my mouth from it thats going take a while to go away.
So after a couple trips with the HDS5 with the same issues i was having with the 520 back to the store it went and i went down a road i never though i would. I ended up buying two new humminbirds one 788c the other a 798SI. I could not be any happier since making said switch, my electronics issues were resolved instantly. I now have sonar that works the way i expect it to and the SI is downright awesome. I have had one dealing with thier CS due to an interference problem on my TM and with the help of Greg Walters who comes to this site and others and a quick phonecall to CS it was resolved. They sent me a free kit that included everything i would need to make the problem go away and worked as they said it would. The rep i spoke to was very plesant and didnt act like i was bothering them like when i called lowrance, i didnt have to wait 3 hours + on hold either. Like i said before i never thought i would have bought Humminbirds and if you asked a couple years ago i would have said no way, i had not owned or used one in years and i always thought Lowrance was a step ahead of them so to speak. Given my recent experience with Lowrance and what i have seen from my new Humminbirds boy was i wrong that assumption for sure.