The advantage of the Dobsonian is that you are getting a lot more aperture for the same amount of money, which means you will see more: more stars, more deep sky objects, more details on planets, nebulae and the Moon.
Also, the Dobsonian mount is simple but very sturdy. The cheap EQ mount will be very shakey and wobbly. And the 4.5" telescope would soon leave you hungry for more.
6" Dob or 8" Dob should serve you well; the 8" very well. The SW Dob from Myastroshop is a little more ergonomic than the GS. Ring or email for best price and tell them IIS sent you.
And once you have more to spend you can get a sturdy EQ mount to put the same telescope on for astrophotography.