Several of us here have Handis in .356/.358. They handle and shoot both. cwlongshots is a rechambered .35 Remington with a 1 in 16 twist. Mine is a rechambered .357 Magnum. with a 1 in 15.5. We can't tell you for sure because we've never shot one against the other, but from what we've posted here, they both seem to be shooting very well. Probably about the same. I'm shooting the 200 gr. Hornady SP. It's very accurate and stabilizing well. As soon as the 225 gr. Sierra Gameking comes in inventory, I'm going to try it. I like boat tails. I can't help you with the pressure question, but I would do it again with a factory barrel. You can't go wrong and it's a lot cheaper. There has been quite a lot of discussion about this recently since Dinny threw some oil on the fire. A search should find it.
Pete