There are no analog sdr receivers since sDr is Digital.
Receiver latency comes from two or maybe three sources, a major source is the USB interface some radios use. USB was a polled port with buffers and while throughput could be ok, every computer I ever used had at least 500ms of latency through it, no matter how fast the computer was.
USB-3 may be much better, but I have not had any radios that came with a usb3 port, only usb2.
Firewire was a Sony interface I think, for Music processing I think that had a very good throughput and low latency and worked very well with the old Flex 3000 and 5000 radios.
All the Flex radios after that use Ethernet. Anan uses Ethernet.
Some radios have the processor in the radio like the Icom 7300 and 7610, the Flex M series, the new Yeasu SDR rigs, the Elad FDM DUO, and others.
Latency can be very low (Icom, Yaesu) or a bit higher (flex M series and the Elad).
On a fair (not great) computer the old Flex 3000 and 5000 could be almost real time, I could listen to my audio going out with just a trace of delay.
I have an MChf radio that converts the RF to I and Q using a sound card chip and processes the data in the radio and it has very low latency, same as the Xiegu G90 I think.