Love the value that Tally has provided to the community. In terms of the differences:

Geyser is more focused on Lightning: we provide lightning addresses to all projects, we integrate with Podcasting 2.0, and soon you'll be able to create projects by plugging your lightning addresses from your wallets.

We help creators engage their communities through content: creators can publish Entries which could be stories or links to their recent podcasts. Moving away from "static" crowdfunding to make this a place where you can publish content which can get you funded.

We enable creators to add 'Rewards' - funders can receive rewards in exchange of donations, which makes it a bit more like an exchange / marketplace, and therefore drive more funding and value.

We also have plans to drive more social components to crowdfunding: crowdfunding is all about becoming part of a community and seeing these ideas happen in the real world. We have plans to integrate with nostr, whereby every funding comment is an event, and users could even chat within a project page to ask questions and even do AMAs ;)

We are more active in promoting valuable projects: we push projects that matter out into the communities thanks to our Geyser Podcast and our Twitter Spaces (which we're planning to do more of).