I have both Arturia FX Collection 4 and this Softube bundle.
I bought Arturia FX Collection 4 €69 with their loyalty discount. If you own their other products you may check if you have a crossgrade price. Or if you plan to buy their other products I remember there is a best crossgrade path and with it you can save a lot of bucks. I believe you can find related discussion on the Internet. Arturia's FX collection 4 has a huge amount of plugin that covers many functions. I mean, huge (30 effects). It covers so many sound effects, delay, chorus, and many more, some are quite cool. Not very sure about their FX collection 2 though. I checked and found it contains 22 plugins which is also a great number, and the price in the link looks OK if buying this single product.
Softube's bundle, I bought it a few days ago by upgrading my Tape licence (note that you need to "give back" you original Tape iLok licence if you use it to upgrade to the bundle). The thing is to me Tape and Model 84 are pretty good and worth the price already.
Somehow Arturia's FX Collection and Softube's Essential Bundle are not really comparable to me. One is all FXs and the amount is huge, another one has Model 84 which is a good synth and also has Tape which I like quite a lot. But this Softube's bundle tends to do sale regularly. Like I said I bought it a few days ago, so I am a bit surprised that there is a sale again, although the current sale seems to be in 3rd party stores rather than their official store.
So, it is not easy to conclude. It depends on what you have and what you'd like to do.