Power Plant Premier

I am in the UK and my 230v mains supply seems to have a lot of 'spikes' which are audible over the system. I would welcome any PPP mains regenerator users feedback on what improvements have been heard (spikes removal or general improvement).
I have the PPP and I think highly of it. My voltage is 120V here in the US. It usually comes into the PPP at 2-3% THD and comes out at 0.4-0.5% THD. I notice a darker background and more "air" around the performers with the PPP, as well as what seems like a bit of increase in dynamics as well. The only downside I have found is that it does not filter out DC on the line, which can cause mechanical transformer hum - I have ordered a Channel Islands Audio XDC-2 filter to take care of the low-level hum in my system, since PS Audio no longer makes the Humbuster DC filter.
The Multiwave setting makes the transformer hum even louder, so I'm not using it at this point, but that may change once I get the XDC-2