Kangaroodort (Arminian Perspectives) has an interesting series regarding Craig Brown's book The Five Dilemmas of Calvinism. I haven't read the book myself, so I cannot give say whether or not it is an accurate report (though from the quotes and from what I know about Ben, I trust it).
However, in this post I wanted to point out his most recent entry in this series: Who's Really Holding the Daisy? I had to identify the doctrine that seems to be the most important to Calvinists, it would be Perseverance of the Saints: that those who have been elected unto salvation are guaranteed by God's gracious deterministic providence to persevere to the end. Calvinists hold to this for both a biblical reason (that we are to be assured of our salvation) and for a personal one (the personal comfort in knowing that one cannot fall away).
But many Arminians have pointed out that this assurance is not real assurance. The observation that there are those who have been devoted to Christ in deed and word sometimes turn their back to God, never to return. This reality stands in stark contrast to the promise of the Calvinist doctrine.
To deal with this reality, all Calvinists that I am aware of have stated that though there are some that seem to fall away, those people were never truly saved to begin with. This does tremendous damage to assurance, for what assurance do you have that you are truly saved? Maybe you are one of the reprobate who simply think that they are saved.
In Arminianism, (well at least most Arminians. There are Arminians who accept Perseverance of the Saints) it is possible for one to lose their salvation, so there is always an evaluation that takes place. But at least we can evaluate. The Calvinist can simply hope that they are really saved. Most Calvinists simply believe that they (and those around them) are saved, and only employ their "never saved" theology when faced with an example of apostasy. This seems like an inconsistency to me.
I believe that the "Arminian" viewpoint better gives the kind of assurance the Bible talks about. This is mostly clearly shown in the book of I John, where over and over again John tells us that we can know that we are indeed saved by examining our works. Our works do not save us, but they do tell us what is going on inside. The logical result of Calvinist theology says that our behavior does not tell us what is really going on inside, something which we cannot even know about ourselves. Where is the assurance of that?
I do not believe that Calvinists are assured because of their theology, but in spite of it. Many of my Arminian brothers have said that a Calvinist cannot being assured of their salvation, but I must interject and say that they are. But, their present salvation must be accepted without referring to what their theology says, for their theology makes no promises there. Instead it is accepted in the same way that Arminians accept theirs, but acknowledging the manifestation of God's grace in our lives. This assurance is in contradiction to their theology, but in compliance with Scripture, and for that, they have my respect.