Does brand really matter when buying 1500uF 16V capacitors?

The short answer is that they should all work if the specifications match perfectly, but the difference between a cheap unit and a reliable component isn't just the voltage or capacitance. It’s about the manufacturing quality, specifically how they handle heat and ripple current.

When you are replacing caps in older gear, especally power supply parts, you really want to look at the ESR, wich stands for equivalent series resistance. Lower ESR is almost always better because it means the capacitor won't get as hot when dealing with fluctuating electrical load. The cheaper options ussually cut corners on internal construction, which causes heat issues down the road. You might get it working this time, but it could fail prematurely, which is what you want to avoid when working on somthing important like a power brick.

Beyond the specs, physical dimensions matter just as much as the numbers. Even if two caps have the same uF and V rating, they could have slightly diffrent diameters or heights. Check the footprint of the original component and make absolutely certain the replacement fits in the space. Capacitors aren't always standardized in size, so a visual check of the body dimensions is essential before you commit to the swap.

If your application is just simple signal filtering or low-power smoothing, many generic parts will suffice. But since you are dealing with a power brick, which is basially a power converter, reliability trumps cost. You are paying for longevity and stable performance, not just the specific ratings on the box. Just make sure you get a reputable manufacturer, even if you aren't tied to a single specific brand.

I really think the emphasis on checking the body dimensions and footprint is overkill for most people doing simple swaps. Most power supplies use standardized dimensions for the cylindrical cans, so if the voltage and capacitance match, the physical fit usually works out fine. Plus, worrying too much about exact heights and diameters might distract from the more important thing, which is making sure the lead style is compatible with your old board. If the leads aren't in the right format for soldering, you'll have a problem regardless of how perfect the physical fit is. Electrical compatibility always comes before the exact width of the capacitor.

While the core electrical ratings appear to be consistent across all your options, I would strongly reccomend investigating the internal electrolyte formulation. The quality of this specific chemical medium is often the primary determinant of long-term stability and capacitance retention, particularly under thermal stress. Since longevity is your stated priority, does the specification sheet happen to mention the maximum continuous operating temprature for these specific cans?