I used to love allegiant, but as time has gone they are not any cheaper than traditional airlines. If you choose your seat and pay for luggage and priority boarding you will actually be more costly than a traditional airline. Additionally, the times they fly are not always convenient.
We had read several reviews that AMTRAK is out of touch and not a great way to travel. We took the train from springfield, il to chicago and the experience was wonderful. It was not a extra long trip and we did not have to find somewhere to park or worry about driving in traffic.