Installing the motherboard inside the Montech Heritage Pro is done by traditional means using the spacers and screws. The openings for the BTF layout are nice and large, so there are no issues with reaching these at all. While grommets would be a welcome addition, there isn't really a need for this case, as you don't get see too much when it is fully assembled anyway.
Once the board is in place, you can install the three 120 mm inverse bladed fans and daisy chain their connectors. As you can see, we already cable managed the IO a bit to clear space for the fans. These actually touch the black cover on the motherboard. While this is a non-issue with the BTF board in use, if you are opting for a classic M-ATX board, you better connect and cable route everything that connects to the bottom edge before installing the fans.
Installing the PSU means that you have to pull off the front cover and remove a pair of screws holding the power supply mounting frame in place. This frame comes with two sets of mounting holes, so you could choose to have it pull air out of the interior upward and out of the case instead of pulling fresh air through the front. We opted to have the intake fan facing forward and started at the top position, but ended up moving the unit to the bottom at the very end, as it nicely hides the IO wires and allows for as much room as possible for the AIO.
Installing the PNY GeForce RTX 4080 XLR8 Triple Fan, which has a length of 335 mm, it becomes apparent how unlikely it will be that you end up having 400 mm at your disposal. In fact, that only seems realistic with an SFX or SFX-L PSU. An ATX PSU does leave the vertical room for a GPU to pass it, if it is installed in the topmost position and is compact enough overall, but that would not consider any power connectors. Also, you still need some room to wiggle your GPU or PSU into place on top of that. Long story short, to stay on the save side, you should probably limit your GPU choice to 360 mm instead.
To get a comfortable amount of clearance for the tubing for the AIO, we moved the PSU down to the bottom position, which worked well as the power supply is only 160 mm long. This will not be a need if you opt for anything smaller than a 360 mm variant, but even so, our large unit fit just fit with plenty of clearance to the motherboard as well. Once again, the rule of thumb should be to pre-connect everything on a traditional M-ATX board beforehand, but nothing is going to interfere with your classic AIO.
Adding a mix of hard drives to the mounting place is straight forward as well, using the supplied screws to pin them down. The mounting holes for the 3.5" unit are elongated, so we made sure to just have the connector clearing the plate and thus use the space we have to the best of our ability.
With everything installed, you can see how the PSU is at its lowest position, hiding the IO wires. Routing the GPU power was a bit unusual, as there is no room at all between the fans on the floor and the GPU to safely, route wires and not collide with fan blades. As such, we ran it along the front on the floor. This is where hooks in this part of the case to use zip ties with would have come in handy. But, again, the Heritage Pro is not meant to bare it all when fully assembled, so you will not even notice. Turning th case around, the cable management is quite good at the center, but lacking a bit at the bottom and top edges. We piggybacked off the power cable to secure wires to at the top, and managed to squeeze cables into the gap on the floor to keep them somewhat organized. The bend radius of wires is always a tricky aspect when using BTF motherboards, but we had no tangible issues once we made sure to be as tight as we could comfortably be with the ATX power and USB wires. From this angle, you can also see how much of the bottom side intake fan will be blocked by the PSU, meaning neither of these fans here will be of much use in reality.
Finished Looks
With all the panels back in place, and the strap at the top secured, the Montech Heritage Pro makes a very posh final impression. This is the kind of case that would look right at home in an historic office or on a sturdy wooden desk surrounded by bookshelves. The center of the power button also lights up in a clean white hue when the system is up and running. Such an attention to detail instead of the generic blue is always appreciated.
Looking at the front, you can clearly see elements of the PSU and some of the glow from the RGB components from the memory. In the rear, everything is where you would expect to see it as well. Montech could have added cable management hooks along the left edge to allow you to bundle up the exterior cables nicely as well, since there is plenty of surface area there to stamp these into the metal.
As mentioned before, the window is quite compact, so most of the components are hidden away. The angle to it means that you do still get a glimpse of the PSU and end of your GPU, but also draws an explicit focus to your memory and CPU at the top left. So, you could still benefit from an AIO with an LCD screen for example. On the other side, you can clearly see the silver 3.5" drive through the vented section. This means heat can dissipate to the exterior surrounding space nicely, but also seeing it is a bit of an eyesore, unfortunately. Another reason you can see that drive so clearly is the fact that this vent does not have a dust filter either.
The strap is just long enough to fit around the top of the case and does feel sturdy enough to pick the full build up for a quick repositioning, but we would not suggest treating this like luggage and utilizing it over extended distances. In other words, while this is certainly functional, its existence is also rooted in the overall look it provides. The hook for headphones is a nice touch and looks great on the case. The only thing that is out of place is the triangle that is part of the design. While it makes sense as the Montech logo has such a shape, you—just like us—may not be successful in having it oriented properly when the hook is fully secured.