Even Calvin had some theological issues. I don't believe in that specific doctrine, nor does it appear to be Biblical.
Now I know a lot of the older Puritan Calvinists, etc. did suffer from assurance issues.
Regarding Arminians, I do believe a bunch of them are saved.... but it's those that understand a lot of what Arminianism stands for, and argue for it that make me worried. To argue for such doctrines in the face of what the Bible teaches is silly. Before I was saved, I knew nothing of election or predestination. It wasn't till after a few months worth of study, getting into MacArthur, etc, etc. that I began to study and understand it. I'm also only as Calvinistic as it's Biblical. I'm still leery at limited atonement, though it's logically deduced by biblical election.
Trust me, these last few years since I was saved in March 2006 haven't been easy. Since I was saved, it has almost been like I've been fighting a world war against Satan, his demons, and the rest of the world.
But for evidence, my life has changed and it wasn't because of me. Remember John Newton? He was setting the world on fire for the devil, then the Lord saved him. Now I never got as low as Newton, nevertheless I swore a lot, listened to ungodly music, sexual immorality, etc. I knew the Gospel, and one night, I knew I had to be saved. I asked the Lord to save me. Then absolutely everything began changing.