A bit harsh. Since I seem to be the only one here that owns a 3-in-1 machine, I'll give my opinion.
I've got a Busy Bee Tools B2229, which is the same thing as the Grizzly G9729; one for Canadian market and one for the US. I've had it for about 8 years now and really like it. Now it won't hog off .25" in a single milling pass, but it is as precise as the operator is. I've added a DRO kit (DRO Pros) on it and it is fantastic with that. I've made tiny parts and I've made large parts. Yes, sometimes setup does take a bit of time but is a couple minutes really significant for an hour of work?
I would not talk anyone out of getting one. Are separate machines better? No doubt. But that doesn't mean a 3-in-1 is garbage.
Small parts or large parts (how many machines this size can swing a 16" wheel?).
Thanks Carbuilder, very valuable point of view. Even if I have decided to go for separate machines, I still think there is a very practical use outside of submarines.
I would go with a decent lathe and buy an XY axis vice for the drill and like the others say replace it with a small mill later. A good used lathe would save you money. Remember the biggest issue with all machine tools is moving the things!