1) With improvement in MLO in the future, WiFi 7 client may break 4Gbps barried using 5GHz/6GHz MLO. We have to wait for such results.
2) Triband WiFi 7 router (without 6GHz band) with proper WiFi 7 client may achieve 3Gbps as well with 5GHz-1+5GHz-2 MLO. This will be similar to EHT240 on 5GHz band (4323 Mbps PHY Link Speed).
3) Qualcomm WiFi chipsets (Qualcomm QCNCM865 WiFi 7 adapters for PCs, and Qualcomm chipsets based flagship WiFi 7 mobile phoes) may be the best in both cases.
4) Test results from Chinese website, using triband WiFi 7 router without 6GHz band, using Qualcomm QCNCM865 WiFi 7 adapter, Windows 24H2
https://www.acwifi.net/28852.html
We can see that MLO got great potential, but you probably need to wait for better FW updates from the router and the clients side. You may also need better driver sfrom new version of Windows/Linux/Android/etc. Apple users have to wait even longer.
4a) Xiaomi BE10000, 5GHz-1 (CH44) and 5GHz-2 (CH149) MLO, similar to EHT240 in this case.
4b) TP-Link TL-7TR13090, 5GHz-1 (CH44) and 5GHz-2 (CH149) MLO, similar to EHT240 in this case.
4c) TP-Link TL-7TR13090, 5GHz-1 and 5GHz-2 MLO, with a region setting which allow 160MHz chanel bandwith for 5GHz-2 band (not allowed in China and Singapore). In this case, it can be similar to 320MHz channel bandwidth on the 6GHz band (EHT320, 5764Mbps PHY speed)