"Its depressing to see so much bad press on these cheap machines"
There's a reason there's so much bad press on cheap machines. They don't hold up as well & beginners have problems sewing on them, they get frustrated & quit sewing when their time & money are wasted over & over again due to junky machines. The main problem with denim is the hems where you have multiple layers of thick fabric, & the machine bogs down. There are some notions (I use the jeanamajig myself) that help with that problem.

The Brother XL2600I is reviewed pretty thoroughly on amazon.com, even good reviews note that it can't handle thick fabrics.

Machine repair is a fairly involved task, & a $300 machine may not last as long as a more expensive machine. I sewed home deco for several years on a 1950's singer with only straight stitch until I could afford a new machine, that old machine sewed better than a new singer ever could. If I were buying on a budget today, I'd seriously consider a used Pfaff, Bernina, etc, from a higher end sewing machine dealer. For your 300 bucks you'll be happier in the long run. Now if you aren't sure if you're going to take up sewing a lot, you may want to go with the $80 model & upgrade in a couple years, that way if you don't sew a lot, you haven't put a lot of money into your closet, the graveyard of sewing machines. You'll also appreciate the higher quality when you upgrade.

I agree you don't need lots of stitch functions, straight stitch & zigzag will serve you well. Good luck, & happy sewing!

Here is a link that might be useful: amazon reviews of brother XL2600I

I have sewn for years and years - first on my Mom's old Singer (straight stitch only); then DH #1 purchased a Montgomery Wards with cams for the decorative stitching (had just given birth to a daughter)in 1960.

Many years later I purchased a $250 Brother - I was NOT sewing denim on it; I ended up spending at least that much for repairs - finally gave it away and purchased a Viking.

You need to realize the less expensive machines WHICH ARE NOT COMPUTERIZED use plastic parts for the working parts (or at least for most of them) which is why the machines won't hold up to working with more than one layer of denim. You "might" be able to sew a patch on denim to cover a hole - I doubt you could do much in the way of making an actual garment, modifying hems, etc.

Save up $3-500 and go to a sewing machine shop (seller, not Walmart). Look at their year end markdowns, trade ins, etc. Right now my dealer has excellent prices on several brands. I am not in the market for a machine upgrade though.