I used to be very active on my MTB until my son was born, towing him in his chariot just wasn't the same so when he got big enough to be able to go on the Mac Ride the purchase was made.
Fitment was shockingly easy, just make sure to read the headset spacer requirements and not just look at the pictures like I did, thankfully I had the perfect amount of room for it to fit. I fitted this to my Giant Reign and the spare headset clamp to my partners Giant Trance, the seat post end is fitted to RockShox Reverbs on both bikes and does not interfere with the function at all, he has no issues with the seating position on either bikes.
The Mac Ride seems expensive until it's bolted to the bike then you understand why when you feel how solid and well thought out the product is, I totally recommend the product to anyone I meet and urge anyone on the fence to just do it, nothing on this planet can give you the time back your missing when it could be spent with you both attacking you fav trail with your little one shouting faster, more bumps, bump bumps.
The only downside to this is a serious shortage on gloves that fit a toddler, come on Mac Ride, sort it out :D
Seriously happy customer.