I've used 3sl plenty on the spider already to great effect and it can be just as good as 3ml. As per usual, trying to brawl with a spider is a bad idea, using the spider and nearby cover to be an evasive distraction and direct fire away from your team is a good idea. Spiders are not meant for murder, though they can definitely do it in the right hands.
Most light mechs will not be fielding both a BAP and an ECM due to weight and slot restrictions, giving this build an advantage against other ECM mechs. Keep in mind that while range is heavily affected, the difference in DPS between 3sl and 3ml is a negligible 1dps drop. LL and ERPPC upgrades are excessively heavy, often reducing the SDR below 5JJ or dropping engine size. Even a 3ml setup will require additional sinks to be stable in long fights.
Once you drop below 5JJ, the Jenner becomes ton for ton the superior boat, especially now that BAP will be an ECM counter. 8JJ is an incredible boon for a light mech, giving it powerful vertical speed and much needed survivability. Ignoring this higher JJ cap is ignoring one of the primary benefits of the spider 5D. It's the equivalent of buying a YLW just to cram a gauss rifle onto the arm, or buying a 3L and not using ECM. Where do you think those three energy slots went?
Anyway, this build/mech is not kind to piloting errors, but is kind to intelligence.
TLDR: This build is not for people who don't know how to do more than point and click. If you don't know how to make the most use of JJs and unpredictable movement, stay away from the spider. Also, a spider with less than 6JJ is just a lightweight jenner with a soon-to-be-nerfed ECM and half the weapon slots.
Edited by TheFlyingScotsman, 16 May 2013 - 04:00 PM.