Here starts day 2 of using my mid 2009 13 inch MacBook pro running High Sierra, used it for around 4 hours last night and seemed like it was working as good or maybe even slightly faster than El Capitan.
MacBookPro5,5?
Yes, Safari in High Sierra is faster in some regards Safari in El Capitan, as Safari has gotten performance optimizations over the years. If you want to make it even faster, you can use an ad blocker.
Booted up the laptop this morning about an hour ago and it seemed to boot slightly faster than last night which is a good thing, it must be adjusting itself to the new os.
The first boot or two always seems to be slow. It must be running some configuration/optimization or something because after that the boot is fast... until you run an update.
So far it has been enjoyable to use. I am thinking about getting more ram for it since it only has 4gb of ram... I think the maximum for the ram is like 8gb for the mid 2009 13 inch MacBook pro. Not real sure if I need to as of yet though since I really don't use it for any really intensive projects besides web surfing, email, and some you tube videos but after being forced to use a windows laptop running windows 10 for almost a year.... I am quickly falling in love with my laptop again... it is such a pleasure to use a computer that just works and works well without constant issues. Apple is the very best with everything from the iPhone to the iPad and to computers.
For your usage, 4 GB should be fine, unless you run tons of Safari tabs or something. However, with more moderate usage like what you describe plus MS Office on top of that, it might be worth upgrading to 8 GB. Office plus Safari and/or Chrome plus email, plus YouTube isn't exactly heavy usage, but it's enough that I noticed that occasionally I would get pauses or beachballs. Moving up to 8 GB eliminated those. However, I see that DDR3-1066 / PC3-8500 SoDIMM memory prices have increased since then so if you find 4 GB to be OK with your light usage, and you don't ever plan on heavier usage with that laptop, then it may not be worth it to upgrade the RAM.
However, a very nice upgrade you can do is SSD if you don't already have one. For light usage, IMO, upgrading from HD to SSD is much more important than going from 4 GB to 8 GB. If you need 8 GB, then the upgrade to do is both SSD and 8 GB.
Very happy I found this MacBook pro on craigslist for $170.00 and was able to get it for $140.00. it looks and seems to work like brand new and the battery has like 645 cycles on it and still gives around 3 to 4 hours of moderate use before it needs to be plugged in. It also came with a brand new in the box original magsafe charger, not some aftermarket charger of questionable quality.
I already had my MacBookPro5,5, and it's in mint condition. It looks like I just got it a few months ago and I've got a Samsung 840 EVO and 8 GB RAM in it so it's quite peppy. I just need a new battery for it.
However, I was also able to get a late 2008 aluminum 13" MacBook5,1 2.0 GHz on Kijiji for about US$150 and gave it the same treatment. I had a leftover old SSD from my old white 2008 MacBook4,1 and was lucky enough to find 8 GB of Transcend RAM for all of US$35 in a flash Amazon sale, so now that machine has 8 GB and SSD too. Since MacBook5,1 is essentially the same machine as MacBookPro5,5, just with a slightly slower CPU, no backlit keyboard, and no Firewire, it feels almost identical to my mid-2009 aluminum 13" MacBookPro5,5 2.26 GHz in usage under High Sierra. It should be noted though that very occasionally with 1080p YouTube, the MacBook5,1 will stutter more than the MacBookPro5,5. However, 720p is pixel-perfect match for these MacBooks, so we're better off using 720p YouTube anyway, and 720p is the default for YouTube on these machines.
BTW, for my white MacBook4,1 2.4 GHz, it now has 4 GB RAM and a HD. No chance for High Sierra because of its age (and crappy GPU), but I installed Neverware CloudReady - Chromium OS 60 on it and it actually works very well. No microphone or iSight camera support, but everything else works, including sleep. The only browser you can run is Chrome, but it is the modern version of Chrome, and its fast, esp. if you have AdBlock Plus installed. YouTube 720p is perfect, Netflix even works.
If you have one of these old machines that only supports up to 10.7.5 or earlier and which are not supported by dosdude1's patches, then Chrome OS might be an option. For example, officially supported early models of the MacBook are MacBook2,1, 3,1, and 4,1. iMac5,2 and iMac7,1 are also supported. It also supports later model Macs, but for those you're better off using dosdude1's Sierra or High Sierra patch if you have SSD.
https://guide.neverware.com/supported-devices/