I’ll second the recommendation for Makita over Ryobi, if you can afford it. Ryobi does make good tools, but it’s their accessories that in my eyes are their claim to fame (hot glue gun, dual inflator, sanders, lighting, etc.). The new brushless tools are definitely a step up, but like ktash, I get the drills in order to get the other tools. Then the drills become my loaners, or used for things like running the drill-powered 3" car polisher, or similar stuff. I’ve handled the subcompact Makita tools quite a bit, and really like the feel and size of the tools, and the power when I’ve been able to demo them, I keep having to remind myself that I already have like 4x more drills than I will ever need, so don’t add the cool black awesomeness to the collection.
With Makita too, if you do decide to expand, much of their OPE is quite good, and they have better options for other tools like the circular saw, recip saw, a trim router, sander, etc. than Ryobi does.
I have the Milwaukee 12V fuel tools, and they are my “daily drivers”, I love the size and weight, and expansiveness of the M12 system. For most regular household tasks, they’ve been good enough. But there are the occasions that they feel a little weak or slow compared to the 18V tools. The Makita subcompact tools combine the best of both worlds, and you’ll definitely appreciate the extra power the first time you need it.
A note on the Ryobi string trimmer(s), I do see two bundled with the 4Ah battery. This one:
https://www.homedepot.com/p/Ryobi-18-Volt-Lithium-Ion-Cordless-String-Trimmer-Edger-4-0-Ah-Battery-and-Charger-Included-P2080/206451828
I have a friend that had one, she thought it was underpowered, I concur with that assessment (we do live in Texas, with thick St. Augustine, so that may play a part). Runtime wasn’t super great, and it also stopped working after a couple months. She traded in for a Ryobi hybrid which was a bit better, but she still borrows my Ego if she forgets to string trim for a few weeks.
The other one:
https://www.homedepot.com/p/Ryobi-ONE-18-Volt-Lithium-Ion-Brushless-Cordless-String-Trimmer-4-0-Ah-Battery-and-Charger-Included-P2090/300339420
With the brushless motor, this one has better runtime and power on paper, but according to protoolreviews (found under opereviews), it suffers from vibration issues. You’ll also find I think that 18V just seems underwhelming on a string trimmer in general, even with the milwaukee and a 9Ah battery I tried for a while, there were times you could tell it was 18V and struggling to keep up. You’ll also find reviews about ryobi batteries not lasting as long as other brands, especially in high drain tools, and you’ll only have one battery with this trimmer. If it runs out, you’ll have to wait for it to charge to finish up. If you aren’t going Ryobi for your tools so you have extra batteries or can justify buying them, that’s another reason to maybe look elsewhere.
For $40 more than the $159 ryobi listed last, you can step up to an Ego trimmer with 2.5Ah battery, which I cannot recommend enough. If you aren’t planning on any other OPE, you might get in the same issue with only having one battery (which charges even slower than the Ryobi), in which case I’d take a look at whatever brand you buy into if you do want to go cordless. If you are looking at other OPE like a blower or hedge trimmer, Ego’s products all around are fantastic, and you’ll be able to get a few more batteries that way. I think the HD-stocked blower was on sale at my HD today when I was in there, I noticed it on an endcap with some signage and I think the price was less than the typical $179. I’d have to go back to look though to see what it was, I don’t see anything online pointing to a deal on it. But you’ll also be able to find deals on Ego stuff a few times a year, and again, everything I’ve used of their stuff has been fantastic. I think you’ll be happier with it in the long run than a Ryobi trimmer.
Makita also has their 18Vx2 tools, which extend into their OPE lines. They are a good way to get more power than even an 18V tool, but still use your 18V batteries. I don’t see the 18Vx2 string trimmer in stores, but if you can happen to find one somewhere, I’d try it out. Even bare tool it’s more expensive than the ego, but it might be an excuse to buy more Makita batteries, and it’ll use the same ones your tools take if you go with Makita.
The 18v platform can be expanded more later if you find that’s true for you. When I started I was just going to do one project. . . But of course, different people have different needs, so there’s no one best solution.