Great question, and I can tell you I owned them both. First I will be fair and say that you are dealing with apples and oranges. One reel costs 100.00 bucks and the other well over 250.00. With that said, I did not like the Echo Ion for reasons that the drag squealed badly, and was very annoying. Whenever you would strip line you would get squeak squeak squeak. When I jumped up to the Guru, I was very impressed, at the craftsman ship, click volume, and drag. However, I doubled my cost to get there. The ION will surely land fish for you too.
I have fished Ion, Guru and Velocity and liked them all. I started with the Ion and moved up to the Guru, only reason was I found one cheap also the same reason that I went from the Guru to the Velocity. I was fonder of Lamson only because they felt like more of a reel but to tell you the truth all reels landed fish without problems. I wish I stopped with lamson and never fished a Hardy
Echo Ion can't be beat for the price. Also, you might look at Allen's large reel offerings. They have really cleaned up the issues that presented when they first came out. I would purchase either with confidence.
Another vote for any of the Lamson models. I have a couple Gurus and some of the older Konics and have caught Steelhead on both. Id check out the Lamson Velocity right now and pick one up on Clearance, cant beat getting that for 40-50% off!!
Lamson..........they are great reels, made in the NW. They are great to deal with and great warranty. The clutch/bearing is easy to switch lhw to rhw. Also you can carry an extra for trips as that is about the only thing that goes wrong with the reel.
I think all my steelhead reels are Hardys. They must work pretty well. Been using them for 40 years. I do have a few others, but they've never gotten much use. Except for the custom Shamburg I've been using the last couple years. But it's not a rational choice.