If you like smok tanks (and I think, personally, that overall smok TANKS have a much better reputation and following) than the mods themselves, it really appears that they can be a very pleasant and hassle free set of tanks for many.
I would say, if you like smok tanks go for it. You may or may not like the RBA deck, I think the feedback on the RBA option has been somewhat mixed, some folks really like the deck, others find it hard to work with due to size and etc.
But, if you want a tank that will do both, it's not a bad option. If you are purchasing specifically for the deck, I do find (overall) that tanks designed specifically for self-built coils (of whatever persuasion) often perform better than those with a secondary RBA deck, as the tank really was primarily designed for using drop in coils. However that is not an absolute, and many folks have been happy with the RBA deck. It's not a terrible way to get a sense of how you may like an RTA or an RTDA or an RBA, and it's a good way to practice without a lot of additional expense.
But, you will be the one vaping and building it, so ultimately it's really up to you. If you think you will still use the tank, even if not loving the RBA deck, I'd say sure, give it a try, and see how it goes.
Anna