There are only “perfect loops”. It it goes around and is not precise you don’t call that a loop!
It’s like a circle... all circles are perfect or it ain’t a circle, it’s called something else.

If you (for what ever reason) don’t wish to use the Quantize tool, then it is imperative that you learn to review your Event List Data.
What you are looking for is first, a clean start.... on the downbeat all the notes that are supposed to sound are there and sounding. If you strike a chord before the downbeat or you press a pedal before that initial downbeat, that event will not be documented.
_ Second you want to check that last few clock ticks of the recorded phrase. If you are recording an 8 Measure Phrase, you want check Measure 008: Beat 4: Clock 440 thru 479... the last group of clock ticks before it cycles back to the top.... each Quarter Note has four hundred eighty clock ticks, 000-479. From beat 4:420 to the next downbeat is what is happening in the very last 64th Note of your
Phrase... probably shouldn’t be anything that close to the next bar line.

If you have Note-On events hanging out in this area it shows you did not keep the crayons within the lines of the coloring book (so to speak). This can play havoc with your loop being perfect.

Whether you Loop Record or not is up to you... the only recommendation I make for recording to Pattern is turn LOOP OFF when recording Arpeggios. You are NOT good enough to stop it between that last clock tick and the top. Let the technology Stop the recording.
Make sure, that if you use a Sustain pedal, that the first CC64 event is an On (127) event, and the very last CC64 event is an Off (0).
Avoid making volume changes in a looping phrase.

Thanks Phil, as far quantizing, I usually found it to be a little to stiff usually changing the feel of any non drum phrases I record. If I could just quantize the first and last event in the loop, it would be enough... Generally speaking, is quantizing really used that much outside of drum programming? Should I really add it to my normal sequencer workflow for all phrases, both drum and normal voices? I guess I could shorten the notes and lower the strength to minimize the movements of events....

Thanks Phil, as far quantizing, I usually found it to be a little to stiff usually changing the feel of any non drum phrases I record. If I could just quantize the first and last event in the loop, it would be enough... Generally speaking, is quantizing really used that much outside of drum programming? Should I really add it to my normal sequencer workflow for all phrases, both drum and normal voices? I guess I could shorten the notes and lower the strength to minimize the movements of events....

This is a great question, sorry I missed it... whether it not you use Quantize is a personal preference. It is not a cure all. If you consistently ‘push’ the time or consistently ‘drag’ behind the time, Quantize can work for you. Even if you are slightly ahead at times and slightly behind at times, Quantize can help tighten things up.

But there is a point at which it will not fix it. Understanding how it works is critical. It is not all or nothing, you can define how it is applied. Why you think it is not used outside of drum programming is curious. We Keyboard players have a higher opinion of our sense of time, than we apply to Drums. We want the drums to be a metronome— while we play freely within the time.

Fact is, all musicians, including drummers (in this instance), really attempt to play in time. Just like singers really do try to sing in tune... if you get one of this pitch correction programs and use it to actually correct pitch, not as an “effect”, you quickly realize that perfect can be very boring. It is our attempt at perfection that is endearing and it is that we are not that contains some of the appeal.

If you set Quantize Strength to 100% (means it will strictly move events to the set value) well you get perfect time, but this is not the only parameter that make it feel right. Duration... length of time a note or chords are held, is just as important an when they begin.

I went to see Duke Ellington when I was about 14, and he gave a brief lecture on swing in the middle of the concert. It was enlightening. Hitting the note on time is important, no doubt, but when you get off of the note is equally important. The combination gives the music a feel, and feel in music is what we define as swing. And you know... it don’t mean a thing...if it ain’t got that swing. The spaces left, the silences give the feel definition... it’s like the black pixels in high resolution screens... the absence of color gives the whole thing definition.

Quantizing musical parts can help tighten up a performance... if your timing laying down Drums is all over the place, probably your timing doing Keyboard parts is as well... the kind of music and the effect you are trying to create is more important than what it looks like in the software. Drum sounds on your synth do not typically respond to Note duration... (usually Drums are Set to ignore Note Off so they just play the entire sound).

Listen closely to what you’ve recorded... especially to the beginning and ending points of your musical segments. If your chord for the top of Measure 9, occurs on the last clock ticks of Measure 8... this is not necessarily a problem unless you later go to Copy measures starting at measure 9.
Suddenly you’ll realize the chord is NOT there. This goes double for Sustain On and Off messages... Recording Sustain into a Looping Pattern brings new respect for the importance of the order of events.

Fortunately, you have a choice - you can Quantize on the way in, but you can also record without, and then Quantize after the fact. You even have ways of trying out the Quantize before committing to it. You can apply subtle timing changes... you can use Quantize Strength so it does not have to be absolute.

If you have a take you really like but you just need to tighten up a region, you can define the area and by what strength you correct the timing... if at all. And since you can set the Measure:Beat and Clock tick for Quantize start and end points.

Aaahh....So I can selectively quantize just the beginning and the end of a loop and leave that swing in the middle.....I think that's just enough perfection... Thanks Again for all your insights, always helpful.