They are made by 2 different manufacturers.
Amongst the differences are the Type A has a Lantiq chipset, the Type B has a Broadcom chipset.
The Type A is better on an ECI cabinet, the Type B better on a Huawei cabinet.
They Type A doesn't do G.INP, the Type B supports G.INP.
The wifi is better on The Type A than the Type B.
Use the Ginp Formula to determine if your vdsl2 connection is with or without G.INP.
Divide your IP Profile by your Sync Speed and the answer is 0.9669 (with) or 0.9679 (without)