The only issue I have with the KTK wallet is it takes more power then others to open and run. So it does stick for a bit when you open and to catch up. I have just dealt with these issues because if you wait they will solve. (at least for me) The developer is busy trying to get the MP out so I am sure he wil focus on making the wallet better next. It is still usable for me.
mine has always been useable, I am using an ssd and an old 630 amd core 4, it's a bit slow once the blocks get down to stupid amounts but I tend to bunch them up once a week now.
Dev has said he will look at the wallet as the transactions aren't the most recent on the front screen either.
All smal things that dont worry me