2x2GB vs. 4x1GB DDR3

[Mud]

May sound like a daft question given silly DDR3 pricing, but will 4x1GB perform significantly differently to 2x2GB? Specifically these kits:

OCZ 2GB DDR3 PC3-10666C7 1333MHz Platinum (2x1GB) Dual Channel DDR3 [7-7-7-20]
(OCZ3P13332GK) £107.99
(£126.89) £215.98
(£253.78)

OCZ 4GB DDR3 PC3-10666C6 1333MHz ReaperX (2x2GB) Dual Channel DDR3 [6-5-5-18]
(OCZ3RPX1333EB4GK) OCZ 4GB DDR3 PC3-10666C6 1333MHz ReaperX (2x2GB) Dual Channel DDR3 (OCZ3RPX1333EB4GK) £269.99
(£317.24) £269.99
(£317.24)

Worth the extra £64? Got a DDR3 mobo sitting here and plan to upgrade to a 45nm CPU when things settle (currently on a G0 Q6600).

 

[Mud]

Any idea if the ReaperX precludes 4x2GB due to the heatsink size?

 

[Mud]

I feared as much! I think I'll assume 4GB is sufficient until it's time to change sockets/prices have come down (in which case what the hell am I doing going from 4GB PC5300 CL3 DDR2 to 4GB PC10666 CL6 DDR3!? I realise the latencies match and the increased FSB doesn't help, but somehow it makes sense in my head...)

Thanks