I ended up going with a smaller Synology as it was actually replacing a RaspberryPi + External drive setup that was failing.

At the end of the day, the Synology was much more expensive, but for me it was worth the trade-off to have a mostly plug and play setup. I can easily move files around in a GUI. I can setup torrents, even configure it to use a VPN and it all takes minutes instead of researching configurations and managing daemons and processes like I had to do previously.

Edit: Also, don't forget to take into account power consumption when reviewing options. There can be a big difference between running an old desktop 24/7 as a NAS versus a Raspberry Pi.

Dig out an old computer and stuff it with a SSD and a handful of HDDs. And you have a decent start.

Buy the cheapest old computer on your equivalent of Craigslist and install TrueNAS. If you want to use a lot of drives, make sure there are enough SATA connenctions on the motherboard.

My setup is a raspberry pi with a large external hard drive running smbd, and it works fine.

I use a Raspberry Pi 4B with a USB 3 JBOD 4-bay disk enclosure, with the disks in a ZFS pool, and it has been working great for my needs.

I'm also in the market for this.

I'm considering setting up a raspberry pi4 nas, and would love to hear pros and cons from people with experience on the matter.

I assume there are faster solutions, but I think it should meet my needs well

I've been running a QNAP TS-435UeX and it checks all the boxes coming in with a mountain of hardware and capability for cheap. Dual 10 GB SFP+ ports, dual SSD slots for raided read write acceleration, user upgradeable memory. It does a lot of stuff and it's an appliance so all the building out and troubleshooting crap is done for you, you just do what you want to do and be productive. The onboard encryption engine can fill the bandwidth of those SFP+ ports even if they're bonded. 4 drive bays, but you can also add another 12 via a couple of different sized expansion boxes.

It's a 1U so the fans are kinda small, therefore it's a bit noisy. The desktop version should be alright though.

Really any PC could be made into a NAS. If you have any old PC laying around you can install Linux to it, and then set up disk shares. I'm assuming you mean an appliance like NAS and honestly the only one I know of, but never used, is Synology.

A year ago I bought an Adjustor AS3304t to replace my xpenology frankenas. I have been pretty happy with it as a NAS, but it is not as good as a Synology. Still out was pretty inexpensive and work well for is primary purpose.

the old PC thing is a clear first choice. Also a WD NAS, preloaded with Hard drives have a very good prince point if you also need the HDDs e.g. The WD My Cloud EX2 with 2x6TB HD is currently 422€ (amazon spain) and each individual 6TB WD red is 200€. (leaving the NAS at 20€). If you get the 24TB version is even cheaper than the two HD combined.

I recommend building your own. Just get something that can hold a lot of disks, and then put in however many you need for your data and redundancy. I like XigmaNas for the software because RAIDz. / zfs.

I've spent entirely too long in the last week or so researching this. You either go cheap but DIY, or expensive but prebuilt. That's not to say that a DIY is always cheaper than a prebuilt, you can go absolutely nuts if you want, but the performance and spec will always be better for the money going DIY. Hot swap drawers are over-rated as you'll maybe use them once a year if that. I can't recommend any specific prebuilt because I haven't used any and am waiting for parts for my DIY build.