I did not notice a lot of machines in Europe like Miller XMT, so called "multiprocess". Are such machines for rig welders in USA only, or there could be place for them in workshops in the Europe.
Multiprocess machines are popular with hire companies, one power source can do MMA,TIG,MIG or gouging if the set is powerful enough and with the right accessories connected, it can even pulse mig I believe although this I haven't tried. This is an attractive option as the machine has more opportunity for getting out and earning money, by nature the power sources tend to be rugged and portable increasing their suitability for site use. I like the XMT, it's a no nonsense piece of kit, welders like the performance on mig and MMA according to the feedback I get. (I've got 14 of them on my hire fleet)
Shipyards tend to like this kind of power source too for the above reasons, but I don't tend to see them in general shop use much, presumably the initial cost versus a conventional 'big square box' type mig set with a separate feeder puts people off.
One issue with multi-process kit is that if you lose one youve lost them all. Also swapping from say, gouging to welding, takes time and 2 seperate sets could be a lot quicker.
I know Jim and from his point of view they are great, he can hire it out as a TIG set one week and a MIG set the next. Perfect for the hire fleet but it depends on your POV.
To some extent the machine will be compromised, but it depends what you are doing. I would for instance not buy one if I was just after a decent DC tig. For a pipe shop however where a really good stick set is a must, with a mixture of tig roots and some site work thrown in, then a multiprocess powersource really comes into it's own. The arc from one of these is arguably smoother and more controllable than those made by a comparable transformer/rectifier set with the added benefit of being portable and more efficient.
As for setup time, I don't think it takes long to untwist one connector and swap a torch, some tig boxes allow you to have the stick lead connected at the same time so the swap from tig root to mma fill and cap is as easy as putting one torch down, flicking the switch from tig to stik, set amps and youre away. Similarly the same can be done on mig sets, with double header feeders, one with solid wire for the root, and one running FCW for the fill and cap.
But it really boils down to what you are looking to do, but I find more and more these days that clients expect a machine to be more than a one trick pony, and want it to excel at a number of different tasks.