Hi all....anyone got any recent experience of this or recommendation of what seat is acceptable? All looks a lot more complicated than it should and I don't want any problem on boarding! 
What kind of seat are you looking at?
We've done maybe 12-13x flight on Virgin with our child. She is almost 3 now.
On lap, she used the Bassinet (Premium is actually very good for this) in flight.
Once she got her own seat, we have 2x systems cause naturally FAA and CAA have two distinct rules for in flight safety for children.
For US Airlines (FAA Regulated, Eg. Delta International & Domestic) - We use the CARES harness - Please please only buy direct from AMSafe's website. They are actually an airline seatbelt manufacturer. There are just fakes on Amazon and whilst say the right things on the label, you could get bounced by Cabin Crew for using it and the stitching is crap compared to the legit one.
For UK & EU (CAA & EASA, eg Virgin Atlantic to/from US or Easyjet to EU) - We use the Maxi-Cosi Nomad Plus - It can be a bit stressful to get it strapped in the first time but once you get the hang of it, its fine and very comfortable for our kid.
Both US and UK cabin crew will look for the relevant CAA/FAA symbols on each seat/harness type so its best to board first and speak to the FSM and ask for the assigned cabin crew to help verify with their iPad (as it has pictures of what the symbol that they are looking for CAA/FAA certificates to be safely used on board).
Worst thing is to get the kiddo in their seat and then have the cabin crew come by and insist on seeing the safety label which ALWAYS happens to be on the bottom of the seat!!!
Just a reminder, US and UK/EU car seats are not 'compatible' from a safety certificate standpoint although lets be honest, they are incredibly similar in spec to keep a child safe in a accident.
US car companies are known NOT to even process a rental if bringing your own car seat from the UK and will insist you rent one of their super uncomfortable ones for you kiddo. If you get stopped by the police, technically it's not a legal and you could get a ticket but honestly, the officer would need to recognise the seat being UK/EU etc so likely very low. However AFAIK, there is NO cross US-UK/EU compatible seat even though Maxi-Cosi & Graco exist in both markets!!!
Any more questions, I'll be glad to help!
