There are people near me that would murder you to get your SOL Blues, if you had some - kidding, but they REALLY love them and buy used one for parts or to use. They are old and failing for the most part, but they are holding on to them as long as they can. Lots of people love their Hydras too. Best is up to you.
Hydras will be newer and have more life in them. I think the winning nature of the sols rests in the rudamentary spectrum and control options. People set them. Ran them high and bright. And they worked. With the new app based controls and 9 channels or whatever, it’s easier to get it wrong. That and most people who still run sols probably really know what they’re doing, and a ton of beginners buy hydras. Were it me, I’d opt for the newer option simply based on wear and tear