The only way to know for sure is to try them both and see which one you like the best. Results are going to vary based on caliber, pellet weight, power level, barrel and/or shroud, and shooting location. I've got a Hugget on a Daystate .22 Regal XL, a Hugget on a .25 Brocock Compatto, and a Neil Clague (NC) on a .25 Air Arms S510 Xtra FAC and each one performs differently.
At full power, my wife thinks the .22 Hugget is the quietest followed closely by the .25 NC with the .25 Hugget being the loudest and I tend to agree. All three rifles have shrouded barrels that the moderators are mounted to. Also, keep in mind that the S510 has two vent holes by the breach so if those are plugged it may change how loud the NC becomes.
In terms of velocity and power, the .22 is shooting 18.21 gr H&N around 808 fps generating around 26 fpe at the moderator. If I use 16 gr diabolo pellets I'm going up to 863 fps but I'm still generating the 26 fpe at the moderator. However, since I've increased the velocity, the volume does increase a bit as well.
For the Brocock I'm shooting 25.4 gr diabolo pellets around 778 fps giving me just over 34 fpe at the moderator on high, 772 fps on medium (33.6 fpe) and 744 fps (31 fpe) on low from a fill pressure of 3200 psi. If I drop my fill pressure to 3000 psi, I get 763 fps (32.8 fpe) on high, 761 fps (32.6 fpe) on medium and 731 (30 fpe) on low. Personally, I hear no difference between any of these but I would expect someone that has better hearing (or if I had a decimeter) to notice the difference especially between high and low settings on each fill pressure.
In regard to the S510, I'm again shooting the 25.4 gr diabolo around 808 fps on high generating almost 37 fpe at the moderator from a 2900 psi fill. If I adjust the power value all the way down I get 460 fps and a power reduction to just under 12 fpe. I also get almost no sound when the trigger is pulled as the pellet is moving so slowly.
Everyone's results will vary but I just wanted to show that there is more to noise reduction than just the brand of moderator you get. For the Compatto, I plan on getting an NC so I can see how much of an affect it has. Unfortunately, the treads are different and I'm unable to move the one for the S510 over to test so until I can get Neil the information he needs for the build I keep using the Hugget as something is almost always better than nothing.