After trying out numerous builds on my SIV, I settled on this one recently as my ride of choice. Although they work on some of the other Vindicator variants, I was getting rolled too quickly with the brawler builds and was not outputting consistent damage using large sets of LRMs. This build takes advantage of the Large Laser (near pulse-laser beam duration) and missile cooldown buffs to increase the mech's damage potential. This guy is a good companion (hence 'Sidecar') for a larger LRM platform that may not have the following: Full motion arm lasers for tracking fast mechs Jump jets Good maneuverability A high hardpoint for a TAG The small set of missiles it has can also hide inside bigger volleys from teammates.
Can't comment on the St Ives, but this looks pretty solid. However, I can chime in about that rather odd engine, as I bought that one for my 1AA as well. The XL245 is a surprisingly well-suited engine for the Vindicators and I consider it to be a kind of sweet spot for those variants able to carry it. As we're going to use multiple energy weapons on theese anyway, additional DHS are going in here for sure. When settling on such a medium sized engine here, it safes some precious weight in comparison to a XL255.
I can echo Aylek, the engine is good. It is also the max on a few other mechs, so it's worth getting.
I plan to purchase the St Ives in the upcoming Black Friday sale (50% off) and this is probably one of the first builds I will try.