I'm in the process of consolidating almost everything into my Fidelity account, where it'll be a 0.2% platform fee. I hold quite a few active funds so it's important to me to find a balance between costs and access to what I want to invest in.
I also have a SIPP with AJB @ 0.35% for some funds that Fidelity don't provide.
I think that between the platform charges and ongoing fund fees, my overall costs will be around 0.6%pa.
I'm wary of putting my retirement account with any platform that brands itself "TradingXXX" no matter what hooks they are trying to grab you with. These platforms make their money by enticing turnover in any way they can. It's like 0% credit cards. Some people may be able to make it work, but most are going to be lured into the freebie and then succumb to less optimal bahaviour, and the subtle change over many years can be quite detrimental.
It's one of those counter-arguments where more friction can be argued to be a GOOD thing behaviourally, as it keeps you from turning over your portfolio depending on which side of the bed you wake up on.