so if I understand right, the 33120A is a bit like some computers were in "the good old days" fine for it's time and maybe still okay, until something goes
In the first place, the 33120A is a single channel generator. Most of the more modern AWGs will have two channels. That's kind of a big deal. I can't do the Valentine Heart with only one channel. Among other things...
I BRIEFLY looked at the User Manual and I didn't see a way to add the 3rd, 5th, 7th, 9th and 11th harmonics to a fundamental sine wave. Maybe I missed it. The maximum harmonic frequency still has to fit inside the bandwidth so for a Siglent 60 MHz unit, so a 5 MHz signal is all we can use as a fundamental if we really need the 11th harmonic. Everything has limits
The 33120A has 10 internal waveforms, the SDG2082X has 196 internal arbitrary waveforms
On its best day, the 33120A isn't any significant fraction of the Siglent with the possible exception that it has lower harmonic distortion. Then again, it has much lower bandwidth.
I'm not going to do it but I suspect an Excel spreadsheet of specifications might be interesting.
I don't know why we're not including the Siglent SDG1000 series AWGs. They are considerably cheaper but, of course, they won't have the features of the SDS2000 series. The only one I can really talk about is the SDG2082X because it is on my bench. Again, the buyer needs to compare the specs.
There is also the SDG800 series that is even cheaper.
Tautech needs to weigh in here. This thread rightly belongs in the Test Equipment forum where the TEA people can weigh in.