In direct answer to your question, suggest you charter a boat for a week to find out. Either in UK to get the local experience (ie weather conditions, tides etc). Or if you want some sun go to Greece and make a holiday out of it. If you go to the Aegean in the summer you will get some serious wind at times to test out whether you like modern boats in heavy weather.

This is exactly what we did (I have a traditional wooden boat in the UK). Ended up buying a Bavaria which is mostly a floating platform for drifting around the Ionian, but I have had it out in the odd spot of heavy weather and have no concerns about its ability - certainly exceeds mine!