@rohlim -
you’ve asked a great question and identifying which conditioner works best, will greatly depend on your other complements . It’s really difficult to provide a solid recommendation but I’ll try. I have a Niagara 1200 and think it restricts the power coming from my Atoll IN300. My system sounded good but my amp lost its punch. So, I plugged my amp straight into the wall and the punch came back. Also, I cannot find any information on the wattage of the 1200, but I’m guessing it is rated at 1200 watts. So, I didn’t know if I was overloading it. Not having surge protection on my amp kept me up at night, so I started looking for a new conditioner. I came across a company called Core Power Technologies that specialize in conditioners (sold by Underwood HiFi). I worked directly with the owner of the company, Walter Liederman and after many conversations I bought an Equi=Core 1800 MKII (up to 1800 watts). I’ll let you read for yourself about the technical aspects of the conditioner so you can decide if this model is what you’re looking for in a condition. I just saw the 1800 MKII has been updated to the 1800 MKIII. I think the MKII is in your prince range.
When I plugged my equipment into the E=C 1800, my amp came back and the noise floor dropped considerably. I’m hearing my components not the conditioner like I did with the 1200. I’m not saying the 1200 is not a nice conditioner, but I felt I was listening to the conditioner and not my components. Below is a link to the website which has many reviews from reviewers and customers. I wish you the best of luck on your hunt.
https://www.underwoodhifi.com/products/equicore