Hello there again!
The Quintet has a more lean bass then the SR5. That's what I noticed right away. Quintet has a lot further extended treble and sounds brighter.
Strong and thick mids are the area in which the SR5 wins. Quintet has more typical chifi mids like you would usually expect. Both of them can be very well equalized which is a bonus. The Quintet is a little harder to drive and really improves it's sound when driven by a hybrid amplifier which is typical behavior for planar in ears.
Quintet is recommended for fans of planar treble. This in ear is pure planar treble since the frequency range is mostly serviced by the other drivers, leaving the planar driver for the treble. Very fast, smooth and detailed treble. Micro detail is not emphasized like in a DD+BA combo. SR5 is a highly resolving IEM with typical BA treble that makes details stand out.
Imaging and separation are very good on both sets but the Quintet is much better. The treble on the quintet sounds so good that I'm happy with this set as my endgame. The treble is so detailed that I have no need for any new IEM with a balanced driver. I simply prefer how guitars sound on a planar hybrid. The fit of the quintet is a downside but I can use my Dunu S&S tips much easier. These tips are a massive upgrade for this IEM that transforms it's soundstage into a super huge stage with top imaging. S&S tips shape the treble perfectly.
My Quintet is driven by a desktop setup consisting of a Jitterbug -> Cayin RU6 > Xduoo MT-602 > JDS Atom amp > 4.4mm to 3.5mm adapter > ISN S16 4.4mm cable > Quintet.