hydraulic holders should be better than er collets ...Weldon shank or ER40 for heavy endmill operations
short hydraulic holders should be better normal ones
i think that shrink fit are better than hydra, but so far i never used them ... i heard that low quality "shrink fit holders" will get out of use pretty soon, thus such stuff should be purchased from trusted sources
er50 is still an option if you like er
i think that collets are ok for drilling; for milling is better to use bigger sized collets or better holders, because of side forcesER25-32 for medium roughing to light duty finishing
also is good to use bigger colets if you are near the maximum shank for that collet size : normal er32 can hold up to shank20, but is better to use er40 starting from shank 16, or something like that
i guess they are rock stars i heard that you too are pretty goodRego-Fix power collets are known to be very good