The Vanguard charging seems to be on top of the annual charges for their funds. So I'd be paying 0.15% as a platform charge and (say) 0.1% for a fund. Is that right? I'm basing my calculations on this, but obviously if they did both then this would make it a lot more compelling.
I think your calculations are right, at least this is my understanding although I could be wrong!
The big one is to make sure you arent paying like 1%+ in fees (many default pension funds are like this) as over 35-40 years it adds up to a silly amount, Candid Money have a good calculator to check how much fees will cost you. Using their calculator plugging in a management fee of 1% and 7% return, investing £400 a month over 40 years you pay £227k in fees over that period, compare that to 0.1% management fee and it only costs £25k, which is the difference between just under £1 million and £750k - when I realised this my jaw hit the floor!!
You can check the calculator out here:
https://www.candidmoney.com/calculators/investment-charges-impact-calculator But if there really is such a cost difference, I'd like to know people's experiences of the Vanguard platform. Is the transfer horrible for everyone?
I think most peoples annoyance comes from the time it takes to transfer the funds in from other pension pots? When I did it with 2 different pensions one took about 3 months and the other 5 months for it to transfer into the account..
Other than that I guess it would come down to how much their fees are in comparison to other companies and what investment options you are looking at. I am aware of people buying Vanguard ETFs through another cheaper platform (I think at the time it was Interactive Investor could be wrong) who have cheaper management/platform fees than Vanguard but they could still benefit from Vanguards investments, it could be worth it but I am lazy and I like Vanguard so I havent bothered, the biggest saving is making sure you arent paying a silly amount in fees (anything from 0.5%+ imo is high)