Magnum 99,
I own and operate a paintball pro-shop and playing field. I am also a Smart Parts certified tech and do all of our gun repairs.
The Tippmann 98 Custom is by far the most reliable gun we carry. While its out-of-the-box performance is not as good as other guns (comparing rate of fire and accuracy), there are many upgrades available to improve its performance.
We have quit stocking Spyders, due to the many repairs they were having. Any gun we sell is backed by a one year free labor warranty. I got sick of working on these guns for free, and we actually made more profit by charging people to work on the Spyders that were puchased elsewhere.
As always, this is just my opinion, based on my personal experience. I think you'll be more satisfied in the long run, if you get the Tippmann.
Also, if possible, upgrade the mask in the package to a thermal lens.
Jon