Bob
Experience with an older model only I'm afraid. Very, very heavy boom; would not work at all unless boat was absolutely head-to-wind; kicker had to be fixed angle to allow sail to roll properly;in any sea-state other than slight - boom movement caused severe problems when (trying to) furl.
Am told it has been improved recently.
PM me if further info reqd.
We have a sailtainer dating from around 1990. You do indeed need to be particular about being head to wind when handling the sail. You do need a rod kicker, but I don't find that a problem. I much prefer the idea to in mast furling as, if the mechanism jams, you can spill the sail on the deck rather than having half a sail flapping in the wind. I have not had the system jam, but there is a cam in the end of the boom which locks off the sail when deployed and this needs TLC.
A side effect of the Sailtainer is that the mainsail is neatly rolled and covered after every use - the sail is kept in remarkably good condition.
Jeckells the sailamkers imported the system and Chris Jeckells is a good contact if you have a problem (or need a sail!)
Very sensible to do some research if you're thinking of getting one!
My experience is that the position of the fixed kicker is critical for reefing. If it's not quite right, the sail will not furl properly and if it furls at all the whole action will be stiff.
I think that this is why you do need to be head to wind to reef; otherwise the wind in the sail lifts the boom a little, and the angle is then wrong.
The upside is that when reefing with a well set up system, it is just a case of pulling the reefing line with one hand, while keeping the tension in the halyard with the other. And, of course, you get infinitely variable reefing, though they do recommend you reef down to one of the full length battens.
Hope that helps,
Rich
PS I have to declare an interest - I have a Sailtainer system (10.6m luff, 3.4m boom) for sale.