Re: What did pre-Steward Lewis do better than post-Steward Lewis?
I love early Lennox, more so than the one that was post Steward.
Young Lewis was lighter, quicker, and more aggressive. I'd say his stamina may have been slightly better as well. He didn't use his size and weight as much though and wasn't the total package yet. Observe him getting outboxed by Frank Bruno before Bruno does a Bruno and gets stopped. I do think that this was Bruno's best fight though and gets under rated.
Post Steward, Lennox gained bulk and got quite a bit stronger which helped him in tiring out opponents. At the same time though it may have hurt his stamina, but due to him fighting in 12 rounders it didn't hurt him all that much. This version of Lennox was sounder defensively and also a safer fighter overall. This version of Lennox is hard to beat, although he sometimes was too conservative which was his biggest weakness perhaps.
I'd say Pre Steward Lewis was the better athlete, and generally more aggressive, but skillwise and effectiveness wise he wasn't as good.