I am a bit biased since I've been heavily in WTC prior to all the China FUD, held through because I believed in the tech and the team and have since profited handsomely as a result.
With that being said, if my mother asked me if she should invest in WTC, I would still highly recommend it since I believe its still in its early stages and has legs to make a run at least into the early $10's and
maybe even $20 by the end of the year. Many people say $30-$50 but I don't see that happening by EOY. The real value is getting enough for a masternode (5000 WTC) so you get future dividends.
How much dividend? That is still TBD.

As far as the next OMG? Technologically they are apples and oranges but they both have lots of potential. It appears at the moment, WTC will have a working product sooner than OMG.

Disclosure: My altcoin portfolio is 40% WTC, 40% OMG and 20% etc (WAVE, LINK, FLO)