I have had some experience of running these with LGB. Some chums and I did a garden event on the Isle of Wight each summer, the last being in 2007. We would borrow a Maxi Train set each year from David Shirley, who was the founder of the wonderful Fort Victoria Model Railway. The set he loaned us each year was usually taken out of stock from his shop and handed over to us complete. I then had the job of opening up the underside of the loco, removing the plug in circuit board AC 'chip' and inserting the DC one supplied as an extra item with the set. I never used the included track , which was standard Marklin G1 and relatively finescale and not suitable for use on anything other than a completely flat and level surface - Most definately not a lawn!
Changing the chip had the effect of allowing the loco to run on DC, but backwards in relation to LGB and Playmobil. There was nothing that could be easily done to reverse the direction of travel, given that we did not own the loco, so a re-wiring was off the agenda. The loco was then oiled up and ran in sun and rain for the two days solid before being handed back, and then presumably sold....
As the loco ran the opposite way round to all other our other items, we usually employed it on a circuit that featured catenary, with a steeple cab fed through an overhead supply, hauling a train that did a lap, swapping over with the maxi train after each circuit. An LGB magnet was blue-tacked to the underside of the maxi train loco to activate automation.
The maxi series was slightly smaller in stature than our other stock and nothing that we had would couple to it, although I have since seen coupling adapters that link LGB to Marklin on e-bay. The wheel standards are slightly heavier than LGB too, and whilst the loco and stock will negotiate LGB points, they tend to clunk a little as they do so.
The mech was rugged and durable, as you would expect with Marklin and the build quality was superb.
I later heard that the range had been discontinued, which is a pity, as it had a lot of charm, but not enough to persuade me to actually buy any!
James