The avgas DA42 could well be an interesting option, but ...
In European touring, and especially flying out of the UK, the biggest flight planning hassle is the matrix of Customs / Avgas.
Even if one ignores the supposedly uncertain avgas future (which I don't believe; far too many planes around the world burning avgas) I would not spend serious money on a new avgas burner. Being able to burn avtur multiplies the destination options several times, especially in more southern Europe and arguably especially in the most attractive and rewarding bits to fly around (Greece).
I know of some people trying to offload their DA42s, having got sick of regular downtime, regular hassles, and being fed bu**!!!!! by Diamond at every turn, but there are no takers except at absolutely give-away prices, and I am not suprised. Most people with money and especially with an IR are not stupid.
After the way they have treated their customers (the Thielert business was only a part of the situation) Diamond will need to win trust, and they will need to prove their product. Looking at some recent DA42 sales figures (down from 85 in 2008 to 38 in 2009) they will also need to convince people that they are not going to go bust while people are sitting on the fence waiting to see how long the Austro engine (on which Diamond's survival IMHO hangs, bearing in mind that this time round the hull maker will be liable for the whole package including the motor) is going to last.
Like a knackered 1984 TB20 for 40k euros, a DA42 is a viable "project airplane" but not for a novice.
There is no issue going to a turboprop from a PA28; it just takes a lot more hours
And it must not be underestimated that more complicated planes do need a higher level of
technical understanding. Any monkey can fly a PA28 and understand it - well to the extent of knowing which knobs to pull out if the engine stops
But this approach cannot be translated higher up.