I believe, the iglide as is, would be perfect for the gopro and iphone. (fixed lens)
If changing of lens is important when you shoot on the steady, and time is precious then the, iglide will suck.
The top adjustments on the iglide is a toy, it takes too long to adjust compared to the hd- series.(When I shoot people they always get impatient when the setup takes too long... bleh. ) So that 's why I changed the top to the HD series.
As long as you have enough weights to counter balance, the iglide would be ok. Hint, just go to a shop with your ideal camera setup and add weights on the iglide till it balances. Don't always trust the manual