There are two models of soft clubs I know. First, there are Reflection Soft Clubs which are advertised in Jugglers World. Reflection clubs are a durable club which is extremely well padded. The spin is different from that of a hard club -- slower, more cumbersome; I find them unpleasant to juggle. Originally they come in several rather pastel hues. This is of little importance as they rapidly accumulate an embedded layer of grime which renders them a nauseating off-grey. Yet, as of St. Louis, even though they are not advertised as "combat clubs" these are the ultimate combat clubs. The care that has gone into their design and manufacture makes them roughly 10 times as durable as Jugglebug soft clubs. Their price is $12 each (plus postage).
Jugglebug soft clubs are essentially disposable. In normal combat usage don't expect them to last 100 rounds. Knobs rip off and the entire foam body of the club quickly begins to slough off the dowel from the first match. Most dangerous is the very thin lay of foam between the end of the dowel. Also the dowels snap frequently. (This may just be the price of playing combat -- I also snapped a Reflection club dowel but the foam body stayed in place where the Jugglebugs generally will break into 2 pieces). On the plus side, these clubs spin much more like a hard club and thus are more pleasing to juggle. At the convention these were selling for $6 each (roughly).
For anyone who learns to play combat with soft clubs and then finds themselves playing with hard -- be careful! Everyone plays more vigorously with the soft clubs since they don't hurt much. That is not the case with hard clubs.
Both types of foam clubs I've used have serious drawbacks. I've used Jugglebugs (which were on sale as combat clubs at the IJA Convention) and Reflection SoftClubs. The Jugglebugs spun like fairly normal clubs but weren't all that soft (especially at the ends where dowel has a tendency to protrude) and lacked durability. In my hands they began to disintegrate after 10 or so games of combat. Their dowels snapped with alarming frequency.
I feel like I should dwell on some of the Jugglebug's good points though since Ben Decker chose to come to the rescue of Reflection clubs with a strategically placed editorial comment in my editorial in Two Ply Press. If you don't play combat, or don't use your clubs to block in combat then these clubs may well be durable enough for you. They do feel so very much more natural to juggle.
But, for combat and for general durability, I have to recommend the Reflection Soft Clubs. The padding at the ends of the dowels protects your opponents far better than that at the end of Jugglebugs. Oh, but at the end of a hard combat session, make sure you have that soapy water and a soft nylon brush to scrub off that grime that will seem almost supernaturally attracted to your Reflection Softclubs. Otherwise you'll be juggling a nauseatingly off-grey piece of foam by the end of the year. On the other hand, would a real combat player worry about the hue, the color coordination, the grime encrustation state of his or her clubs? I think not.
Outside of combat and maybe teaching beginners to juggle clubs, I wouldn't recommend any type of foam club, unless these foamy Joes turn out to be better than the other two with which I'm acquainted.