Right then, I suppose I'd better be more precise.
The keys wiggle...more than is desirable or expected.
And they ping...more than is desirable or expected, though I could probably live with it.
Better? My apologies for the imprecision of the first version.
Edited to add: Is there a substantial acclimatization period with these mechanical things? I mean, are the issues I've listed the sort of thing that one typically "gets used to" with a mechanical keyboard?