I like Gillies the most of this group. But goalies are extremely hard to predict...so the easiest thing is probably make cases for and against for each and apply Buttonwood's proprietary Hannu Toivonen Ranking (TM)- without a doubt THE best goalie prospect ever.
1) Gillies
For: Great combination of size and skills, moves well for his size, solid technical ability, winner and solid mental make-up
Against: Some awkwardness movement (size related). Played on a defense-first team collegiately (a 93% svp would not be that high otherwise).
Buttonwood Hot-Take: Needs a more diverse resume (pro, international) before he can be anointed the GOF (Goaltender of the Future). Getting significant AHL time is exactly what the doctor ordered in his development... so feeling good about him. 4.33 Hannu Toivonen's out of 5)
2) Ortio
For: Pretty good pro experience, most athletic and the closest to the show of the 3, a Fin
Against: Moves small sometimes, redundant with Ramo, projects more to a 1B replacement level guy than franchise building block.
Buttonwood Hot-Take: I'm glad he's in the system. Still young in G-years and has some upside, he is the bridge from the present to the future. Hopefully he can prove himself an NHLer this year and continue to improve. He does need to work on his positioning/size. (3.75 Hannu Toivonen's out of 5)
3) MacDonald
For: Has all of the tools, has a heavy workload in the Q and seems to handle it well, lots of 'upside'
Against: Still a long way away/difficult to project, doesn't really have a 'wow' factor (IMO)
Buttonwood Hot-Take: Too young to make a call. Generally dislike investing 2nd's on 18 year old goalies when they could be anything by 23-24, but he adds nice depth to the most critical position. Theoretically, read for the AHL as Gillies graduates to the NHL. (3.5 Hannu Toivonen's out of 5)