I'll start by saying that I'm a lover of this mod, so anything I put out there is probably a bit skewed in that direction.
The J.S. mod definitely makes the game harder, but does give you a few breaks. Armor is a good example; combat armor weighs just 12# instead of the normal 25#, and it affords more protection by adding damage resistance to the standard damage threshold. The downside is that with 5 strength, you only start with a 100# carry capacity. That can be viewed as a positive, though. Before, I used to have insane amounts of things stashed in chests at The Lucky 38, and found myself caught in a trap of constant inventory manipulations...now I spend more time immersed in adventure, and still have more money than I can spend at mid levels.
The mod really re balances many things, more intelligently, I think. After all, he was the main man on New Vegas development. I've said before that the game just feels more complete and natural with it in. People seem to be somewhat polarized about the mod, so the best thing is probably to try it and see if it's for you or not.
Btw...I usually play Very Hard, hardcoe, Dead is Dead..and yes, I get killed a lot