If its a private game, either. To each their preference and have them swap guns to try both.
If at a field, I'd go semi.
If they feel out gunned, they may not enjoy the experience as much.
Its hard enough for experienced pumpers to be competitive at a commercial field, let alone a 1st timer.
Alot may depend on the guns the other players are using.
A first timer with a Trracer against an Ego...bad news.
It no wonder that the rental pumps were hardly used at the field I played at.