OK, my server is up and running and I've sent out my first campaigns so I can now give a good review of the product.
It took a few days to set everything just right. In part it was my fault because I failed to mention that I had content on my domain (good note for anyone else who is thinking about ordering, make sure you emphasize the fact there is content on your domain, if there is any), but as soon as Teo got around to it, it was fixed within a few minutes. During the setup process, I can say that the communication was on a satisfactory level, he would get back to me always within a reasonable time frame. I am a reasonable person and don't expect someone to dance around my needs all the time just because I purchased a product, so from my POV, it was overall fine.
As for the campaigns, I tried several major providers and they are all inboxing, with an exception of gmail which, at this moment it time, inboxes some of my mails, while others go to spam. All things considered, getting into gmail inbox is not easy and I might need to play a bit with wording etc to get higher inboxing rates for gmail as well, but it works as well as I expected and I believe there are things I can do on my part to make it work even better for my specific needs.
As for the mailing software, it is intuitive, easy to use and offer some very nice insights, including the info about who opened your emails, which I find really useful. Creating campaigns is simple, importing your contacts even simpler and if your lists contain multiple fields, you can pick from some of the most common options to determine what those fields stand for (names, addresses etc).
Overall, so far I am very happy with everything and if things continue to go the way they are right now, I believe we are looking at a long and fruitful cooperation.
My rating: 8.5 / 10 - it isn't absolutely perfect, as nothing is, but it is by far the best service of this type that I was able to find, especially considering the costs.