I don't think so, imho people will ensure in the 4th year that any niggles they have are dealt with prior to warranty running out and as such those with the 1st generation cars, which I think we agree are the best ones anyway, may well have the most optimum versions. Look at Steve snrs car, apart from his alloy inserts and the steering coupling thingy at the beginning there has been nothing else, my 1st gen FD needed nothing, which I feel is replicated by most FD owners. The GD is now more popular after the 1st year than the FD was after it's first year and so the effect of that will of course be the that problems may be more easily picked up. I wouls suggest that by year 5, if you utilise the warranty properly, you have probably got a pretty good motor for another 5 years.
As I have said previously, the i30 seems to be the most "switched on" of the range, perhaps due to it sitting in the most highly competitive European segment and so Hyundai, possibly rightly, concentrate on it more.
The bigger issue for me and many of the "Hyundai bashers" is that rather than really ensuring that the i20, ix20 and i30 all compete at the top of the game in their respective segments, the i30 gets the most attention at the expense of the i20 and ix20 which do rather fall short of the standard set by the i30. Hyundai then spread themselves even thinner by attempting to pierce into the luxury segment with the i40, where again they have got close and for the first year or so looked like perhaps they had succeeded, but now the niggles have started to appear where they would not in the oppositions vehicles just makes them easy meat for critical comment.
None of the niggles should really exist in a new car, but they do and no doubt also some exist in other brands, the difference really is how quickly your manufacturer deals with it and Hyundai really are poor in that respect in the UK market at least. Something as simple as replacement brake calipers or alloy wheels in a warranty replacement should not see owners with their cars off the road and waiting for 3 months to be sorted, Ford would have a caliper replaced within a couple of weeks maximum!