Yes. Upgrading from PS1 to PS2 or PS3 will get you the ability to run those locos in the same block/on the same track/at the same time.
Aside from long life (which to me has never been a problem), what is the advantage of LED in a loco? If your power supply is so marginal that the draw of those grain-of-wheat bulbs overcomes capacity, you've got other problems. I had over a dozen locos that I've upgraded to PS2, and have never regretted it. Those old Korea-built Weavers & MTHs run as well as or better than the new. I've also upgraded a couple of old Lionel Pulmor-powered locos, but don't recommend it unless you want the challenge.
