im at the point of being able to play most hard-some another songs now after my 7k practise, it might be more so a matter of you adapting to certain patterns faster then others, just play more random songs that you enjoy and slowly work up , i would also suggest that you step out of your comfort zone and start doing low levels of the patterns that you find annoying and slowly get used to them, ive been told autoconverts even in 7k lack diversity, there are several places you can get nonautoconverts of variety,
t/147552 entozers list of songs, personally i drifted away from these to get more variety, as they have said you dont need to rely on these alone for moving up although they were very helpful to start with for me personally
http://www.mediafire.com/folder/ses64a2853od1/IIDX_BMS pre bms songs thanks to davteezy a lot of these and they can be helpful or you could also take random pending songs for your difficulty level that are nonautoconverts
i dont really have the experience in 7k to judge how bad it is using autoconverts so i cannot say to not or to use them, that is up to you all that i know is the general census on autoconverts is bad