LifeStrategy is the sort of thing you'd normally hold in a SIPP, where you'd expect it to start at 80 or 100% and gradually trade down to safer/more cautious stuff and eventually cash as retirement approaches.
Actually, I see they have Target Retirement 20xx funds specifically for that.
If I didn't already have something like that in a SIPP, I'd probably go for either one of those first.
For long-term growth since I already have the pension in place, I'd pick the lowest-fee (OCF) fund with the highest risk. The fees are what eat your net returns, and the risk generally means the price moves around a lot - which is OK so long as you won't need to sell at a low point.
This isn't advice, obviously, because I'm not qualified and your risk appetite will be different to mine.