I have been on Novorapid and Lantus since diagnosis a few years back with no problems whatsoever.
As Jaylee says, basal seems to be the key. If you can get that right, the Novorapid does the rest a treat. I've reduced my basal by half this year, and still rarely have to use fast acting through the day. Novorapid seems to take around 3 hours to cycle through rather than the advertised 2 hours. Also the Lantus seems to run out of steam around 18 to 20 hours making the evening meal dose of Novorapid a bit higher than any daytime ratio.
I did ask for a change to Fiasp at my last review, but as my GP pointed out, the Novo and Lantus is working perfectly, so why mess around.