We haven't yet launched! Until now we have been working on a really impressive semantic technology. Because of the broadness of applications that may be built upon this amazing technology, during the past few months we have been thinking/working on a few different use-cases. A month ago we picked one and developed a prototype for show-case and made executive summary and pitch deck for it. After getting a few intros, last week we were able to get confirmation from a great investor whom we really value. His opinion and possible involvement is a great deal for us. Within the past two days and after a lot of discussions, we have come to this point that we can change the final product (still using the same underlying technology) and offer a different model for the business. This new product/model makes more sense for us and we believe may have better success in the market. Now we have this big question that: Whether we need to stick to our previous product/model in our upcoming meeting with this VC or present the new one? Or just present our technology and offer both options? Is such a change "bad" and would negatively affect the VC's opinion about "us"?
You may want to consider showcasing the more narrow, focused application which will be (ideally) your more capital-efficient beachhead that proves the product and market fit. Meanwhile, I would present a few select slides or datapoints from the original presentation as something that showcases the broader opportunity which can be pursued at a later milestone or development stage.
Yes it's totally ok to change the product & business model before meeting a VC and even after meeting him. Your job is to find product/market fit and almost every company goes through many iterations and even major changes to achieve that.
The only thing you shouldn't do (if you're raising money) is ask the VC to make the decision between both options for you. If your goal is to close funding from this VC within the next 90 days, you will need to project confidence that whatever choice you've made and that you're raising on, is the right one. If on the other hand, you really do want their opinion and aren't planning on raising soon, presenting both options and getting feedback can be very valuable IF, this VC has relevant experience in your space. One of the worst things a VC can do is offer up an opinion with conviction without having the experience or really even passion for the space the entrepreneur is in.
I'd be happy to talk to you by phone as early stage fundraising is an area I help a lot of Clarity members with. I've also answered a lot of other Clarity questions on early stage fundraising which can be seen from my profile here: http://www.clarity.fm/tomwilliams