I'm down to my last oil change worth of Total Quartz Ineo 5w30 507.00 oil. I see from another forum that there is now a 507.00 0w30 oil. Any opinions?

Spec here:

http://lubricantes-online.com/WebRoot/StoreES2/Shops/eb2659/53F5/98EF/7DF7/128A/586B/AC10/1416/A052/Helix_Ultra_Professional_AV_0W30_tds.pdf

The only point of using 0W30 is if you drive in extreme cold, the spec 0W30 has to meet is pretty much same as for the 5W30, except 0W-30 flows as well at -35degC as 5W-30 at -30degC.

 

So unless you are planning a quick Easter trip far into Polar Circle :p , 0W30 won't really make much difference.

I was mostly interested to know if during warmup phase the engine might be more economical with the 0w30.

Below freezing and starting from cold, probably yes, 0W30 will flow better. Above freezing it is not as clear cut as e.g. at 40degC 5W30 oils can actually flow better than 0W30 ones, even from same manufacturer. This is due to additives in 0W oils specifically targetting lower viscosity at extremely low temperatures. I'd say in the UK 5W30 still works out better.