Former England international Olly Barkley knows better than anyone that not everything that glitters in French rugby is gold.
The former Bath and Gloucester fly-half has just pitched his tent at the Scarlets for the rest of the season after two eventful campaigns in France.
While Welsh rugby is in the grip of an unprecedented exodus of players across the English Channel, Barkley's experience is a salutary warning to any player thinking life is a bed of roses in French rugby's Top 14.
"You can bet your bottom dollar it is going to be a big challenge, regardless of where you are going to play," he said.
"I think you have to embrace it and try to make the most of of it because if you don't you will miss out.
"It's not better or worse, it's just different how they do things [in France]."
The 23-times capped England international signed a four-month deal with the Scarlets in February after he left Grenoble a year early because he did not share the same "rugby concept" as the club's director of rugby Fabrice Landreau.
Barkley takes care to choose his words when he talks about his experience at Racing Metro, where he played 10 games, and Grenoble, whom he left in February after only five games.
The 32-year-old, who joined Racing Metro from Bath as injury cover - a "medical joker" in French rugby parlance - during September 2012, admits playing in France did not match his hopes and expectations.
"Things weren't really working out as I wanted them to work out at Grenoble," said Barkley.
"It wasn't really the environment I was led to believe was going to materialise - that is the most diplomatic way of saying it.
"I felt after a year and a half in France, where I really enjoyed myself and learned an awful lot... it was definitely the most challenging 18 months of my career.
"You have to integrate into another language, way of playing, another culture and the way they do things which is very different to the way we do things in Anglo-Saxon Britain."
Now French rugby is a magnet for world-class players from across the globe, who are all attracted by the big pay-cheques on offer and the chance to test themselves in the most unforgiving league on the planet.
Culture and language
Barkley left Racing to make way for Ireland and British and Irish Lions fly-half Jonny Sexton - who has expressed reservations about his move - and is not surprised Roberts and Lydiate, in particular, have needed a period of adjustment to life in France.
"You go out there and it's going to be challenge because there are so many barriers to jump over before you can begin to think about playing well," said Barkley.
"You have to adjust to the style of life out there which is very different, the people, the culture and the language.
"There is definitely an adjustment period - you can see that with the way players are playing at the moment.
"If you can get through the adjustment period, you can really benefit because the league is very different to here and is very unstructured and perhaps not as organised.
"Some players will enjoy that, and some will find that hard work."
So what can Jonathan Davies, the Wales and Lions centre, currently a team-mate of Barkley's in Llanelli and who will join Clermont in the summer, expect on the field?
"We are far more organised over here and we like to be far more organised about how we approach a defence and break it down," said Barkley.
"I think the French see it as a weakness if you cannot play off the cuff and you cannot adjust to what is in front of you.
"There is more than one way to skin a cat, but that is their approach."
Barkley, who made his England debut against the USA as a 19-year-old in 2001 before he had played a full senior game of rugby, may have returned to the UK but, despite offers from clubs in England and France, has found himself in Wales.
While Welsh rugby may be in the grip of a row between the Welsh Rugby Union and the Welsh regions about the player drain and funding, Barkley is clearly impressed with his new surroundings at Parc y Scarlets.
"I am loving being back here and being part of a professional set-up, with a good medical team and a more professional way of doing things, compared to what occasionally is the case in France," said Barkley.
"[I was impressed] with the facilities, the team and the coaches, who I heard very good things about from people I spoke to, and I have always enjoyed watching the Scarlets play when they throw the ball around.
"It is just another challenge, another opportunity and I know what the Premiership is about and I hadn't played in the Pro12 before and I felt it was something I would like to take on."
Barkley says he has "nothing organised or set in stone" after his stint with the Scarlets comes to an end in May.
But what it is like as an Englishman in Wales as both nations gear up for the Six Nations clash at Twickenham on 8 March.
"I think the boys have picked up on the fact I am half-Welsh, so that has been at a minimum," said Barkley.
"My mum was born in Newport, so I have a lot of cousins in Newport, who I had a bit of banter with when I signed here."