A/V system power cord upgrade and mains block advice?

I was wondering would Merlin Tarantula Mk6 be worthwhile power cord upgrade for my Yamaha RX-A1010 and Cambridge Audio 751BD? Also should plug my system straight into wall sockets rather than into my 35£ APC mains block with surge protection since I have read that mains block can have negative effect on sound quality wih 500£-1000£ components? Any Advice would be appreciated.