The Eos is a great gun, shoots nicely and is reliable provided you look after it, lubing, batteries etc. It's heavier than the top end guns and the on/off asa I'd recommend changing for a purging asa but apart from that it comes with a locking feed neck, freak junior barrel, BOB, can be capped at 10.5bps ramping and doesn't suffer from drop off like the Ion at higher ROF so offers great value!
Sadly SP have stopped producing them but if you can pick one up you'll have no problem getting bits as servicable parts are all interchangeable with Ions
A great step up from a mechcanical marker on your way to a Luxe