Totally agree with Peter - good eyepiece & barlow are a must. Just a different scope then! Nearly all your viewing will be at low power, with occasional higher for planets, moon. My 4.5" is f8 (focal length 900mm), so my 21mm EP gives about 43x magnification, which I find just right for most viewing. High magnification at our aperture usually costs too much light on deep space objects. Don't get too caught up in collimation, as our small scopes are a little more forgiving in this area I understand. I do collimate with a Cheshire, but I think the minor adjustments I (rarely) do make no perceptible difference to the views. Somebody with more knowledge than me about this may like to comment.
Great advantage of our 'littlies' is ease of use - I have mine set up all the time, and can whip it outside in one hand whenever the whim grabs me! Quick cooling too. A real joy to use, and at low power they're nowhere as bad as some "Bazooka" owners would tell us! LOL
Cheers -