Hopefully any of the other forum members that own one will see your post and share their comments but so far you are the first one to mention them on the forum.
Having said that … while other people’s comments about the knowledge and service of a particular business can certainly be very helpful, I would always keep in mind that you are the only one that can feel what you feel on a mattress and I would be cautious about about using anyone else’s suggestions, experiences or reviews on a specific mattress (either positive or negative) or review sites in general as a reliable source of information or guidance about how you will feel on the same mattress or how suitable or how durable a mattress may be for you and in many if not most cases they can be more misleading than helpful because a mattress that would be a perfect choice for one person or even a larger group of people may be completely unsuitable for someone else to sleep on (even if they are in a similar weight range). In other words … reviews in general won’t tell you much if anything about the suitability, quality, durability, or “value” of a mattress for any particular person (see post #13 here).
It would also be worth reading post #1 here about what I call “simplified choice” mattresses.
Every layer and component in a mattress (including the cover and quilting) will affect the feel and performance of every other layer both above and below it and the mattress as a whole so while the top latex layer is relatively thin (only 3 cm or 1.2") the firmness and “feel” and “comfort” of the mattress will come from the quilted cover, the latex layer, and the top few inches of the zoned and fabricated support core underneath it so there is no inherent reason to be concerned with the thickness of just the top layer itself.
Having said that … the only way to know whether the Bruno will be a good “match” for you in terms of comfort, firmness, and PPP (Posture and alignment, Pressure relief, and your own personal preferences) will be based on either careful testing (which of course isn’t possible with an online purchase) or your own personal experience.
There are also no “standard” definitions or consensus of opinions for firmness ratings and different manufacturers can rate their mattresses very differently than others so a mattress that one manufacturer rates as being a specific firmness could be rated very differently by another manufacturer. Different people can also have very different perceptions of firmness and softness compared to others as well and a mattress that feels firm for one person can feel like “medium” for someone else or even “soft” for someone else (or vice versa) depending on their body type, sleeping style, physiology, their frame of reference based on what they are used to, and their individual sensitivity and perceptions. There are also different types of firmness and softness that different people may be sensitive to that can affect how they “rate” a mattress as well (see post #15 here) so different people can also have very different opinions on how two mattresses compare in terms of firmness and and some people may rate one mattress as being firmer than another and someone else may rate them the other way around. This is all relative and very subjective and is as much an art as a science.
When you can’t test a mattress in person then the most reliable source of guidance is always a more detailed phone conversation with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart and who can help “talk you through” the specifics of their mattresses and the properties and “feel” of the materials they are using (fast or slow response, resilience, firmness etc) and the options they have available that may be the best “match” for you based on the information you provide them, any local testing you have done or mattresses you have slept on and liked or other mattresses you are considering that they are familiar with, and the “averages” of other customers that are similar to you. They will know more about “matching” their specific mattress designs and firmness levels to different body types, sleeping positions, and preferences (or to other mattresses that they are familiar with) than anyone else.
If for any reason you aren’t confident that a mattress you are considering would be a suitable choice in terms of firmness, “feel”, or PPP then the options you have after a purchase including the the exchange/return policy (and any costs involved) would also be a more important part of the “value” of an online purchase just in case (and in spite of the “best judgement” of everyone involved) the choice you make doesn’t turn out as well as you hoped for. While you can’t make direct or “real time” comparisons with other mattresses with an online purchase … with a good trial period and refund policy you can at least test the mattress in your bedroom instead of a showroom with little risk (outside of the time you spend sleeping on it and/or returning it should that be necessary).
There is more about the 3 most important parts of the “value” of a mattress purchase in post #13 here which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists based on suitability, durability, and all the other parts of your personal value equation that are most important to you (including the price of course and the options you have available after a purchase if your choice doesn’t turn out as well as you hoped for).
While nobody can speak to how any specific mattress will “feel” for someone else because this is too subjective and relative to different body types, sleeping positions, and individual preferences, sensitivities, and circumstances and you are the only one that can feel what you feel on a mattress … the Bruno mattress uses 100% natural Dunlop latex and 48 kg/m3 (3 lb/ft3) polyfoam which are both high quality materials so there are no lower quality materials or weak links in the mattress that would be a cause for concern in terms of durability.
If after a conversation with them you have “enough” confidence that it would be a “good enough” match for you in terms of PPP to try it and if it compares well to the other finalists you are considering based on all the other parts of your personal value equation that are important to you then it would certainly be worth considering.