@dev/null. Sorry, didn't realize you already own an X3. In that case, if what you're looking at are comparably priced, I'd definitely go with the X1 over the GLA, and not just because this is a BMW forum. It really stood out compared to the others we test drove. We test drove a lot of makes since March of this year, and when I have time can post some thoughts (or PM me if you want) -- compared the X1, X3, X4, GLA, GLC, QX30, RDX, Q3, XC60, Evoque, Discovery Sport.
Don't know what kind of price range and other factors (warranty, mileage, finance, etc.) you're considering, but as we were assessing our options and going through the process, these were two that I remember that we were really considering getting before pulling the trigger on the X3. These were purchase considerations, no lease:
1. 2016 X1, loaded with everything we wanted (Estoril blue, M sport, xenon lights, backup camera, can't remember the others), original MSRP new 48K. It was a recently retired loaner with 7K miles or so, offered as CPO elite (warranty through 2021), dealer was offering 0.9% APR at 40.9K pre-tax. We really wanted this one, but apparently someone else beat us to it, as due to work schedule we couldn't go until the weekend, sold around Memorial day.
2. 2016 GLA, sport package, xenon lights, backup camera and a few other things, original MSRP new 45K. It was used with 10K miles, not certified, but original factory warranty good through 2020, dealer was not MB, but Audi or some other reputable, non-shady major dealer (can't remember), dealer had no special APR to offer, but was selling at 28.9K pre-tax. While we liked the X1 more, we were in a situation somewhat similar to you (car primarily DD for my wife, not necessarily needed as our main hauler), and at the price, with the options it had, this was hard to pass up too. I mean seriously, when the difference for a used GLA can be over 10K less, it really had us thinking. Wife would've been just as happy with that one at that price (we think). We could've had this one, but decided to pass because we tend to keep cars for 5+ yrs, so while a good price, wanted something we wouldn't regret.
Anyways, hope this helps and I'll try posting on those others we test if that'd be of help.
Best,
BTL