Glad to field this question.
This is really a tough call. I would definitely say get both if you can but I understand that for most people that choice isn’t always an option. I can help guide you (and hopefully others) in this.
First I will talk about the 2.8 and the assembly. The 2.8 kit does require some tools and a little patience but the build is really fun and you will learn a lot. The instructions here can give you an idea of what you are in for. The 2.8 and instruction set are based on a few years of development and tons of feedback and most people regardless of experience level can do it. I also manage the technical support team and I can safely say that we will back you up 100% of the way. Need some clarification? We’re on it. Screw something up? A new one’s in the mail…it’s their goal to make sure these ROVs get in the water.
Okay, so the build isn’t that bad…but should you wait for Trident? Good question.
Let’s start with timing. Trident won’t be ready for a while. Our Kickstarter has a November target that we are working towards as I write this. So if you need the capability right now, go with the 2.8.
Second, what about building and hacking your way to success? Trident will also feature the ability to add and/or modify the software and hardware–we’re obsessed with giving the community the option to make their own tools. To what extent and how soon some of these things are ready on Trident is still TBD, so if you have a strong need to get add-on’s and hacks ready and working right away I think the 2.8 might be a better bet. The 2.8 has wires already outside the electronics tube for i2c, PWM, and servo channel. Also, this forum is full of folks who have already done their own mods and hacks.
What about performance? The 2.8 is designed as an observation-class mini-ROV and as such performs really well in tight spaces with little current it has a moving camera platform to look up and down. The Trident on the other hand is much more suited for running search patterns and covering more area quickly. It will be fast, agile, and able to track in straight lines. Simply put, if you are interested in looking for something go with Trident, if you are interested in looking at something 2.8 may be a better option.
Finally, if all above are good to know but don’t really change your mind, you’re probably left with one question: Is Trident going to be much better and therefore worth the wait? All other things above equal, yes, the Trident will be the best low-cost underwater exploration tool ever developed. You can pre-order it here.
To your unrelated question about the Spanish store: yes, they are an Authorized OpenROV Reseller and are amazingly helpful and knowledgeable folks.
In closing, If you or anybody else has any questions about this, post here and we can help clarify as best we can. But still…two is always better than one .