Thanks guys I think I will go with the Mag Z-boost spool rather than the older Mag-Z. To Andres - hard question and I think it will depend on what weights you will use the most. if compact baits 25-40g and going for distance, I would go Mag Z because Mag-z is more of s distance mag brake and spool diameter is better for distance with heavy baits but the SV-boost spool I have is more allround braked spool and the 34 mm spool will do better with lighter weights. My 21 Zillion SV-boost does well with 25-30g bomb casts into headwinds, stabile and a tie with my 12 Exsence DC but I would like to gain a few more yards if possible with a Mag-Z boost spool while hopefully still controlable in headwinds, its for a rather specific use.