Lead Acid or Calcium car battery?

[RobW]

I know there are a few full size car experts on here so hoping they can help with what is probably a simple question.

Need to get a new car battery on way home from work tonight so it is going to have to Halfords jobbie as they stay open a bit later.

Questions is they have a lead acid for £87 or a calcium one at £97. Presumably a calcium one is "better" but what am I getting for my extra £10 - potential extra life or better starting power or is it just marketing hype? I know it is not a lot but it is another pair of buggy tyres!!

Car is 6 year old peugeot 407 estate, 2.0 HDI diesel, 95k on clock and probably do about 15,000 miles a year in it - it is the family hack so it does everything from daily commute of 30ish miles mostly on motorway to short local trips all weekend and then some longer journeys to race meetings and taking kids back to university etc.

Any advice appreciated

Cheers

Rob