I have had AirArms S410 2009 model, S410 carbine, Marauder, MFR, Blizzard, and FX Whisper. The HW100 (i believe is a 2008 or 2009 with quick fill) is better than most listed. I would rate of those listed as:
1. MFR, 2. HW100, 3. S410. I favor the sidelever action of the S410 and HW100 over the MFR. The accuracy of the 3 are all very good to outstanding. The shot consistancy is HW100, MFR, then of course the S410 as it has no regulator. s410 still has a great shot curve. I favor the HW100 first for the quick fill, then S410 followed by the MFR... unless you have a custom quick fill installed on the MFR. Now for the bad news... The HW100 is equal to a .22 shot as far as sound. There is a new model that is due out with a full barrel shroud... but no idea when it will be available. You will need to call some dealers? Precision, Ponoma, Straight shooters..? They all have the HW100 Listed...