Here's what I gather:
Elgin Baylor was the greatest offensive forward of his era, and also in the eyes of his peers, the best player who played forward - he's as gifted a scorer as anyone, a guy that could give you 60 points in the NBA finals and was ranked among the top players for league scoring through his prime - he's a superstar with that ability to just know how to best exploit his talents to get games won. As far as the other end of the court is concerned, he played defense but was not noted as a stand out defender, and from what I can see is not particularly gifted with wingspan or reach/timing necessary for racking up blocked shots or anything anyways, though he did gather a decent amount of steals from what I can see - doesn't matter though, his peers would all agree that despite being nowhere near Gus Johnson on defense, you pick Baylor over Johnson if you had to choose between the two to be your teams star forward. He was a very elite rebounder. If we strictly look at TRB% and sort of ignore his TRB's, Baylor was still a spectacular rebounder. A better rebounder than Lebron James, but not as good as say, Charles Barkley - right around Larry Bird's level actually with his peak TRB% season being slightly better than Bird's best rebounding season. As a facilitator he is more like Kobe Bryant, his aim is to score first obviously, but he's a deft passer when he sees an opportunity. He can play anything from PG to PF on offense, as he can run the floor and was actually the keystone for the 60s Lakers to counter Bostons pressing defense by stalwart guards like K.C. Jones. When pressure was put on the Lakers guards during a game, Baylor, the forward, stepped in and handled all ball handling duties in the backcourt. So at the pro level Baylor could play smaller ball than Gus. Late in his career when Wilt joined the team, he also swung to PF after he had lost much of his quickness (and also because Wilt provided plenty of size to clog the lanes as it is so a "6-5" PF wasn't going to kill the team on defense). Baylor's bread and butter was definitely the small forward spot though.
Gus Johnson was the greatest defensive forward of his era - his offensive game was solid too, and because of it Nate Thurmond was on record as saying Gus was the best "all around" forward of that era due to his impact on both ends (this is during the first 2 or 3 seasons they were playing just before Gus started to become plagued with injuries). He could give you 40 points occasionally, and in a spectacular kind of way too. His game was less consistent in where he applied pressure than Baylors though, as he might only contribute 8 points the next night yet have something like 22 rebounds 5 blocked shots and 9 assists so it's not like he disappeared, he simply imposed his abilities onto other widely varied facets of the game. Defense always came first though, his role wasn't to be the scorer of his team, the coaches never wanted him to play that role like Baylor's coaches did. He could literally guard 1-5. He guarded the toughest player on the opposing team, and unless they were a big center like Wilt or Kareem he often was capable of giving them hell. For example, from testimonial, nobody guarded Oscar Robertson (a PG) or Jerry Lucas (a PF/C) better than Gus. And he was at LEAST as good of a rebounder as Elgin. I haven't factored his TRB% yet but I'd be willing to bet he's just as elite if not a little more on the rare occasions he was healthy. He was more injury prone than Baylor. His passing ability was spectacular but I suspect if he passed in volume he maybe a little high on turnovers because some of his passes tended to be extra dramatic from description and from what little footage exists so he never got as many assists as Baylor. Due to Gus Johnsons athleticism, strength, and long arms he played both PF and SF on offense equally well at the pro level. He was so physically dominant that he actually played center in HS and college despite Nate Thurmond - a 50 greatest NBA center and a beast himself - being his high school teammate.
I did find their playing weight ranges and know roughly how tall they were to give an idea of their size. Baylor was probably about 6-5 w/o shoes (think Kobe Bryant, Michael Jordan, Charles Barkley) and Gus was in the same ballpark though Gus might have been closer to 6-5.5 (Metta WP height). Baylor weighed a stocky 225lbs most of his career and he fluctuated between 212-236lbs and Gus Johnson was an absolute tank in the Lebron mold, weighing 235-240lbs most of the time but fluctuating to as high as 255lbs and he never was fat. Baylor has a known 11' 10" max reach, Gus has a known 11' 6" "standing-jump" reach. Gus is clearly stated as the more powerful leaper in his era and I'd imagine he could probably touch 12' or above if he was going for max. Both have huge "connie hawkins/MJ" hands and could palm the ball like a Grapefruit which helped their dramatic passes and ways of scoring. Gus is described as getting his head level with the rim on his best jumps, Baylor is not, Baylor is known for hang time (which is more a function of body control) not absolute height reached when jumping. Gus is also explicitly described as taking off from the free throw line and dunking during games, and it is stated in such descriptions that "even Baylor couldn't do that". Gus also appears to have a much longer wingspan than Baylor, this is just from eyeballing how they look in footage.
. He suspends himself so high in the air when he goes straight up for the block that he props himself up on the backboard and appears to hover there for a brief moment - the hangtime on that play is MJ-like, and he recovers immediately once he lands and jumps almost just as high for a second block 
