I just recently got a single wheel BOB clone (TW Bents folding trailer) and my one piece of advice is to consider your size and weight in relation to the trailer weight. I've done a few test rides with the trailer loaded so the total towing weight was probably somewhere around 50 lbs. Since I am 260 I found I was able to control any wobble or lightness in the front end caused by the trailer with minimal effort. If I were substantially lighter then handling might be an issue.

On my aluminum frame hybrid I found no flex and no major handling problems that could not be easily countered. As for the cornering -- there is a kind of a cool feeling once you get used to it. You will find some push-pull sensation as you start off or go uphill, but I found this a minimal problem. The sensation might be more pronounced for a smaller, lighter rider.

For us the trailer is the way to go since my son is only 8 and my wife is not yet a strong biker so to get our gear out to where we want to go I will play pack mule for a few years. Eventually, I plan to hang it on my son's bike as sort of a brake so he can't get too far in front of mom and dad.