Two ways of the ways I use BA, and this comes down to Integration
One of the ones I remember most was a MegaMek battle years ago (and I use this example a lot) had a Clan med nova going up against a IS Company that had a lot of assaults and heavies. The largest Clan mech I had was a Timber Wolf E, and I think I also had a Mad Dog (not the Prime or C) or Huntsman, a Ice Ferret A, and some other fast mechs. I know I was facing 3 assaults- one a Steiner Banshee IIRC- that were waddling along behind the skirmish line. Now we used double blind for that server so I ran my mechs closer to the IS force while firing arm weapons since they were carrying Elementals, Rabids and I think a single Salamander point. I had gotten a few cERLL hits while avoiding damage when I stopped my mechs behind a hill. It provided partial from most of the IS mechs but more importantly it dropped my BA into a sheltered position, since dismounting is when they are the most vulnerable to opposing fire. The place I dropped the BA was ideal since it was in the open but had elevation changes. I could jump the BA forward in a skirmish line and keep them out of sight/fire until the IS mechs got closer. And to make them get closer the Clan mechs started walking backwards, now being able to fire all appropriate weapons. Since I out-ranged the Inner Sphere company, as planned when taking cERLL and ATMs, it forced the IS with its more plentiful armor to run forward. Most of them had 4/6 speeds, which slowed them with the elevation changes and made conditions better for my BA.
The Steiner Banshee ran forward to position itself in a depression to fire on the mechs, which gave it partial cover. Unknown to the IS player, I had a Elemental point that had jumped forward into that depression- either it was going to be occupied or it would put them in a good position to respond to the Spheriod mechs. Even though I had not fired any SRMs previously, I still did not fire them- the Elementals were protected from the other mechs in the company b/c of terrain and the mech could not fire into its own hex. Leg Attack! Got the crit . . . rolled a 12 . . . pristine Banshee has a leg blown off from BA it never knew were positioned in that depression. Best result from that turn, but the other BA did pretty well too . . . one other leg attack happened with damage, and it failed the PSR. Other points fired off their weapons, peppering mechs with lasers and SRMs. The BA threw the IS advance into chaos b/c after that leg blown off, he moved mechs forward or backwards to avoid the BA in his midst. Next turn I did not get any more leg attacks but the Banshee stayed down (I think it knocked its noggin, so KO'd) and the Clan mechs walked forward to isolate the mechs that had went towards them to avoid BA. The BA spent the last of their SRMs, getting more crits that turn. The IS player felt his force was in danger and so started retreating to his edge- battle over, time for the mop up!
So, when Clan I tend to use BA to hold a skirmish line, with mechs & armor able to move through hexes occupied by BA/Inf it does not work as well as it did under TW, but it still forces that avalanche of armor to move more cautiously. BV balanced IS-Clan fights requires that Clan player to chew through the more plentiful armor of the IS to start knocking them down.
Second example, last year we had a tournament set during the Jihad (use MUL, pick a faction, pick a unit, see what was available) . . . first round, with a 5k force only 2 of the 7 had BA. The two won nearly all their matches, which had the interesting effect of folks adding BA for the second round. This year's tournament (13 players?) I have seen a few BA out. Anyway, I was a FS Avalon Hussar's regiment and they started packing on the BA during the Jihad b/c they were sitting on/near a factory. So, IS Std and Grenadiers for me! If you read above, the 2 hex moving Grenadiers do not really fit with my praise of the 3 or 4 jumping medium suits. But this is good, makes me use something I have not before and consider how to get use out of it. First round I had no transport, so my 2 IS Std and 1 or 2 Grenadier were on their own. They generally pushed forward like a SRM Carrier or HBK4G- a 9 hex bubble of pain. Only a few mechs willingly came into their range . . . and ran away when they could afterwards since running into a SRM20 & SRM4 (used HK- SRM5 & MagShot) was unpleasant for damaged mechs.
After I got the second 5k (we now fought for 3 hours with 10k each, had to use previous force) I included a transport VTOL- I want to say a Sprint. I also added a Grenadier HK(NARC) to support my mechs & Harrasser. Deployment changed a bit. Starting Turn 1, the VTOL was aimed at a hill or woods while starting at a elevation high enough to avoid terrain and loaded with one of the IS Std (LRR). Turn 1 move was simple- straight ahead to where I wanted the BA to drop, jump capable BA go out the doors and land in a wooded hex (+1 for Inf Tactics, +1 for jumping and +1 for light woods) which made them harder to kill. Turn 2, the VTOL reversed course to land and pick up Grenadiers . . . one game was the regular HK, another time I used the Grenadier HK (NARC) which ended up in the middle of the map. The Grenadiers sitting in woods or on the side of the hills in the center of the map cut down on the movement of my opponents but they were pushed forward to pin enemy forces in place so the advancing mechs and armor were able to get better shots. My Grenadiers racked up some mech & armor kills over the tournament.
So with slower BA armed with SRMs, MLs, MagShots or best yet the LRMs of Hauberks, they can very effectively do area denial for cheaper than you can do with a SRM Carrier.