Having had both a15 and l16 in a 1200 id leave a15 due to tunnel and x member mods. If in a 120y L series with the steering geometry issues or mod stock x member to fit L.

Lots more options for l series I feel power wise. And a mild L20 will be great.

Do a15 if you want and if not enough power sell it and do l series.

Braking is fine with stanza struts and handling is fine in my car. A little more front heavy (10kg is the motor weight difference)