We'd recommend the Nissan T32 X-Trail Series II from mid-2017-onwards and Subaru S4 Forester (2013-2018), since they both make strong secondhand buys due to their reliability, economy, ease of operation, spacious interiors, practicality and strong resale values.
The reason why we'd buy the 2017-onwards X-Trail Series II is because it standardises Autonomous Emergency Braking (AEB). With the Forester, you'll need to skip the lower grades 2.0i-L (manual-only) and 2.5i-L (auto only) for the S and XT for that important safety technology Subaru calls 'EyeSight'.
The X-Trail comes in front-wheel drive (2WD) or all-wheel drive (AWD) configurations, but the Forester is AWD-only. All automatics are of the continuous variable transmission (CVT) variety, which priorities fuel economy but can make the engine drone under hard acceleration. Subaru calls its CVT Lineartronic while Nissan dubs its version X-Tronic.
Our recommendation is to check the service and maintenance history of any car you buy, to ensure every interval has been met and carried out by a proper dealer or brand specialist. This is especially important with the Forester, as it is a slightly more complicated vehicle mechanically. Note that all Subarus of this generation require six-monthly service intervals, not 12-monthly ones like the Nissan, which might be an inconvenience.
We'd steer clear of ex-rentals as they tend to have a very hard life (both models were popular with such agencies), though they're almost always the base X-Trail ST and Forester 2.5i-L grades that end up as rental fodder.
If you're thinking about diesel engined versions, the X-Trail in middle-range TL and up-spec TS guises switched from the earlier (2014-2017) Series 1's 1.6-litre turbo-diesel to a much more powerful and effective 2.0-litre unit, so that's worth remembering. In the Forester the 2.0D equates to the mid-level petrol models in terms of equipment levels.
Finally, we recommend a mechanical check-up to see that your potential used-buy has not been subjected to punishing off-road treatment. While both the Forester and X-Trail offer good ground clearances, they're not for off-road use, only light gravel, snow or trail driving.
We hope this helps. Good luck.