I'm not really qualified But I had a spare stick 5gig but it will do. M3 isn't starting up as good as I'd like so I figure I haven't much to lose. I'll download the Mageia 4 Beta 2. I had problems installing into M4 live so I'll do a system upgrade. Downloaded H4 beta 2 full by Ktorrent without incident then saved it to a stick with isodumper. Upgraded M3 to M4 no problem. then deleted the orphans.
When I was in 4 I had a slight difficulty configuring the update sources the ticks wouldn't stay ticked. the DVD sources were defaulting to being ticked and as those sources where on a stick and update was only looking for a DVD that wasn't going to work. Generally the whole process was very smooth and easy.