That's just a can of worms waiting to explode. @Clark Griswald has a thread on this as well.
My POV is figure out the port density you need for higher speed devices / needs and then that will narrow things down quite a bit. Most options start with 4 ports of which 3 are usable.
I run a DIY setup and collapsed ~6-8 devices into a single box and use a 5GE NIC instead of paying threw the nose for a switch. I have 2 ports going to the cable modem to take advantage of the over provisioning and exceed 1gbps. I have 1 going to my AP @ 2.5gbps. Keep one as a spare. $200 for the card and double the speed of a 2.5GE w/o having to deal with the gouging of a 10GE option. I use the spare port occasionally to sync my laptop with the server that has a NAS / Raid setup that pushes 400MB/s+.
For a 2.5GE switch though it's all about finding the right fit / price. On the HW level they all use the same stuff under the hood. If you're thinking managed switches then it comes down to the OS / GUI / CLI options. There's fewer options moving to 5GE though than 2.5GE unless you step up to 10GE and then you only get a couple of ports that do 5GE in the mix.
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