Before the 75, I only used 90s on a M for river Smallmouth and 110s on a MH for pond and lake Largemouth. I've got some 75s that I want to use for river Smallmouth. They're heavier than a 90 but lighter than a 110. I can't decide on a M or MH. 

I like to use a 7' MH fast rod, same a I use for my 110s.  Works just fine.  In a pinch, I also threw it on a 7' H rod, which worked equally well.

I throw it on a 7’3” MH

I throw mine on a 6'10" MH/F action Lew's Mach I rod paired with a Lew's Tournament MB reel spooled with 10lb. Berkley Big Game line.

I would normally use a MH baitcaster, but I’ve been throwing it on a medium action spinning rod  for that last few days. It loads the road about as much as I feel comfortable with but it fished just fine. 

Fury 704 /30#braid

I use MH casting, M spinning, and my M MF crankbait rod for my WP 90s. Will probably use any/all of those for the 75s I inevitably purchase. I've been preferring my M spinning rod lately for the same reason Scott F said. The M rod just loads and casts better. Reel retrieve speed juat feels right too.

I have been throwing them on a G.Loomis 844c IMX with a High Speed Daiwa Zillion and 12lb Mono. 

Gloomis GLX 802 with a Daiwa Tatula 100H Type R

7' M/F 20lb braid, same setup I fish the 90 and 110 on. 

6’10” Falcon mh/mf cranking rod.