Too me, it came down too money and performance. I was able to sell my used IMXs, spend the money on a ALX Ikos rod and still have $50 left over. I think the IKOS line is some of the most versatile rods I have ever used. Especially the Hammer and Promise. There just isnt much i cant do with either of those. Great build quality and sensitivy for half the price of a IMX. Dont get me wrong, the IMX Pro is a great rod, but I didnt see the extra $150ish dollar difference. That's my view of the IKOS line.
The Zolo line, IMHO is a better rod than the IMX pro, and still cheaper. Feels lighter, and more sensitive. The zolo line doesnt seem as versatile, more technique specific compared to the IKOS. Although, the deputy can do a whole lot. I prefer really light low profile reels like the MGX and ALX from Abu, the Zolo line just feels more balanced and comfortable in my hand with those reels compared to the IMX pro. I dragged a point with a Carolina rig with a Zolo Dragger, and a IMX Pro. Same reel, line, weight, bait, hook etc. The Zolo was more sensitive. That's really the only back to back test I have done between the two.
I also dont believe there is a better rod on the market today in the $150 price point that can compete with the IKOS. I do not own a spinning rod from ALX or Loomis, so I cant speak on that line. I hope this helps.