I actually use both those systems. I started using INK's iLac and TGB's BIAB a year ago and since TGB brought out their LED lamp I have been using their gel polish as well.
I absolutely love INK! I find iLac applies really well and lasts well too. They now have their strong rubber base (Flubber) which definitely makes the nails stronger and the gel polish last longer but it's not quite as strong as TGB's Builder in a Bottle (BIAB), which is an amazing product! If you do a lot of overlays or extensions I would highly recommend it. I have found their gel polishes very good too. They have lots of colour choices!
As most my clients have infills I tend to just file off the gel polish but I have soaked off and both gel polishes soak off easily but both will take longer if you have BIAB or Flubber underneath. (BUT both ARE soakable, which is a big plus!)
I have always found INK very professional. Deliveries have always been prompt as well. TGB have had their fair share of teething troubles which hopefully they are puttIng behind them but be prepared for popular products to be out of stock and very slow delivery times when they have a sale on.