Riptides got a buff to their Ion Accelerator. It's now S9 standard, S10 supercharged. This let's it compete with everything that isn't strictly heavy armor. It comes with Battlesuit Support System and Weapon Support System built in. This means it can be in engagement with say another vehicle, suffer no penalty from Big Guns, and is allowed to fall back and shoot anyways. Even against heavy armor if you run Kauyon you can use A Tempting Trap to add 1 to wound rolls anyways against an objective marker. Or you can Nova Charge once per game if you have the means to fish for Dev Wounds. The biggest boon I think is it comes with a 4+ invuln. With 14 wounds it's a monster to chew through. It's basically a giant scary mech that can threaten an objective. Even if your opponent can charge it, they can never lock it down. It has Fly so even if you surround it, there is no desperate escape. Or if you want to get crazy you can charge enemy tanks, preferably something with Blast weapons that can't shoot in engagement range. WSS negates any penalties from shooting with Big Guns, and you can fall back and still shoot on your next turn. Your opponent will mostly likely have to skip their turn falling back so something else can shoot at the Riptide, or abandon the objective.
It's just strong enough that you can't ignore it, but it's tanky enough that you hesitate to commit fire to it. For a model that big it's highly mobile which makes it pretty easy to reposition and cover multiple sight lines. At 190 points you are paying a premium for it, but you can bring 3 of them and they can form the main thrust of your aggression. You'll want to bring Crisis Suits still simply because they are massive, and expensive, and you will still need other units to support them. They wont carry games for you.
Broadsides sort of offer what Hammerheads do with access to the Heavy Rail Rifle, but they have a smaller profile. Even if you only brought one for some reason, for 80 points it gets you access to an extremely threatening "fuck this guy in particular" gun. They hold your back line and will immediately punish any heavy armor that tries to enter their firing lane. They can even take a seeker missile if you really want extra anti-tank for cheap. Something I hadn't considered, but might decide to try, is placing them in strategic reserves. If your opponent is foolish enough to leave their backline open, you can squeeze one in and do some serious damage to artillery that is sitting on their home.
What I've seen broadsides used for lately is in Experimental Prototype Cadre. Take High-yield missile pods, Twin smart missles systems, and weapon support systems. Broadsides love both Experimental Ammunition and Threat Assessment Analyzer. Broadsides have a natural FNP 4+ against mortals, which means you can turn your missiles hazardous from those stratagems and still have a 4+ to ignore damage if you fail.
Compared to other Crisis Suits the main draw is that both Broadsides and Riptides easily outrange them. A Sunforge team must get within 12" to melt their target. Depending on your table this is going to be more or less difficult. If playing on GW terrain you will always have at least one or two lanes that a Broadside can guard from deployment. A Sunforge has to either Deep Strike or run up the board. Starscythes likewise have to be within 12" because if you run Burst cannons you're just wrong. Fireknives are the only team that have any kind of range, and they are solidly meh.
TL;DR Riptides are big stompy tanks that are highly mobile and hard to take off the board, but do enough damage that they can't be ignored. They are big bullies. Broadsides offer a lot of backline firepower that can cover firing lanes (assuming GW layout). Heavy rail rifles do the work of Sunforge teams without having to get within 12". With missiles a single broadside can output more shots than a whole Fireknife team.