I like overhead joins as they provide for a longer time to get established, gives you the opportunity to see the field and the windsock (which is invaluable at uncontrolled fields) and keep you separated from the downwind traffic by altitude. I use it here in the US with my Aero Commander on smaller fields as well, as it provides time for it to slow down. I even asked for it at Stockton last time, which is very much controlled and has two long parallel runways, and got it. The 45 degree join in the US is a suggestion or recommendation - you can ask for whatever you want.
The 45 degree join works fine if you're set up beforehand for it. If you're descending into the downwind on your 45 degree, then I'd argue it's more dangerous than an overhead join as you're now descending into traffic that could be behind or below you with no way of spotting them. This happens daily in the US - rarely do you see people being established at pattern altitude at the 45. Therefore in reality, the English systems is safer, I think.
I think the safest way would be to climb to pattern altitude, i.e. come in lower on the 45, but that's obviously not very practical.