I'm not sure how big of a deal the insert feature is. I'd be interested in hearing why it is important to you
I've talked about this before. Generally interfaces don't give you inserts.
I want inserts, because I have some outboard gear I would like to use.
In particular, I have a Behringer V-Verb pro reverb unit, which is very very nice.
Snobs out there might bad-mouth the V-Verb pro, but those snobs are idiots.
I also have a Behringer Virtualizer 'something or other' effects box.
In addition, inserts will be useful when recording with the Boss Acousctic Singer VE-8 harmonizing box,
by taking the guitar input from a daw track, while singing into the mic, and monitoring on headphones, thus keeping vocals
separate to guitar.
That anwers your question TAE, but here are more observations.
The SSL 12 looks more like a competitor to the Focusrite 18i8, and is not dis-similar in price.
Both offer 4 preamps, and 8 more ADAT channels. The 18i8 has a further 4 line in jacks on the rear.
The Neve 2 channel interface is similar in price to the SSL Big Six, which offers a hell of a lot more (including channel and mix bus compression and inserts).
The SSL 12 32-bit converters will make little difference to the amateur, or indeed a pro.
All of this kit will be made in china, so 'Genuine Neve preamps, and SSL preamps' should be taken with a pinhch of salt.