I've had this set for a couple years and while its not the smallest dildo (six inches in length and an inch and a half in diameter) It is a fairly smooth ride with the hardest part being the first inch.Once the head is in I found it smooth and comfortable as it has a good amount of flexibility to it.
The set comes with a couple of O-rings in different sizes so ithe harness can be used with different dildos and the dildo that comes with it does work as a suction cup dildo too, though its not the best suction cup.
The harness and stockings look fantastic on and are great quality for what you're paying so even if you decide to opt for a different dildo later on (I replaced the dildo after a while as its jelly so it has a limited lifespan) its a great harness set to have.
I've used a few Tantus toys with it and find they work well in it, fit well.I'd say the Tantus silk would be best for a begginer and with its smooth texture would be less likely to irritate/cause an ibs flare up.
Hope that helps 