The PPL(M) is no more - new microlight pilots now train for the NPPL Microlight rating. That covers both flexwing and 3-axis machines, but I believe that differences training is now compulsory before you switch from one to the other.
tartan42,
There are now quite a few 3-axis microlights which are pretty similar to light aircraft; very similar indeed in some cases like the Jabiru where there are both microlight and SEP versions of the same machine.
The top-end 3-axis microlights are actually quite capable tourers - the one I used to have often took me from London across the Channel and the Irish Sea; a return trip to somewhere like La Baule was perfectly do-able for a weekend jaunt. Payload is an issue, but if you're on your own it's not a problem.
They are similar to fly to a SEP machine, though their lightness and lack of inertia make them more twitchy than heavier aircraft.
Operating costs are cheaper than C of A machines, though some PFA types would be just as economical.
It is legally possible to hire microlights now, but I don't think very many are actually available for hire yet, so it's certainly not as easy as finding a C152. You also cannot carry a passenger in a hired microlight.
Have a look at the
BMAA website for more information.