Riggle VTAF question

Hi, all.
I have a question which I hope will prompt plenty of opinions and help. I listen to albums via a Rega P-25 and Jolida phono preamp. I added the Pete Riggle VTAF successfully a couple of years ago (or maybe just last year). It raises the tonearm as you may know. Well, I just cannot seem to make myself use the shims for the cartridge that Pete suggests, so basically, I can't really adjust for VTA since when the adjuster wheel is rotated until it can't rotate anymore (to the top), at that point only my 180 gram vinyl plays with the arm level. Otherwise I am always slightly higher at the rear of the arm since I haven't put on the shims for the cart. The reason I don't want to use the shims is I'm now using expensive (to me) carts (Shelter 501 and the Denon 103R -cheaper but to my ears sounds better than the shelter for some reason) and I don't want to mess them up. Bottom line questions:
1. What are your thoughts on using or not using the shims? 2. Is there a way to raise the platter with a mat or something that could solve my dilemma? I had been using the Iron Horse acrylic platter (same height as glass), but just switched back to the glass right after I installed the denon cart.
3. Has anyone else out there had this problem (er. . . dilemma)? If so, what have you done?
4. Not totally off topic, but while I'm posting, any reason why the denon might be sounding better than the acclaimed shelter? (I know - the denon is acclaimed too) The styli sure sit differently. And, if it matters, I use the Baerwald alignment by using the Geodisk (not rega). Thanks in advance for any comments about any of this.
Had the 501 and was under-impressed ,with all the rave reviews touting Koetsu-like mids??
As far as VTA:Is the VTA not low enough,except for 180gs?
It seems odd that after adding the Riggle adjuster your arm is too high except for thick records. Could you do this:

- Get a lead from an automatic pencil and lay it down on top of the headshell in line with the 3 large holes (assuming you have a Rega arm). It should be basically in line with the cantilever of the cart.

- Get a nice, square business card and draw some accurate parallel lines on the back, length-wise.

- Place the cart down in the middle of the record, with the platter not spinning.

- Put the business card up on edge on the record behind the cart.

- Get down and with one eye closed, line up the pencil lead with the lines on the card.

- Adjust until it is level.

If as you say, if you can't get the pivot low enough then you will have to use the spacer between the cart and headshell. For the Denon 103, some say performance is actually improved on a Rega arm with a brass spacer which adds more effective mass to the tonearm. This assumes your counter-weight can balance it all out without going off the end of the stub.
I've had the exact same problem as you with a modded Rega arm I installed on a Thorens TD160. I think shims are a bad idea, compromise a tight headshell, cartridge interface.

In my case I had to cut down the height of my armboard in order to get the arm lower than level with the vinyl. I'm not sure you can do this with the Rega tt. You can also try the Herbie's record mats, they have a thicker one which will act to lower your arm.

I'm also using the Denon 103R in this setup, sounds nice to me. I will add increased mass to my arm at some point in order to improve tracking on this low compliance cartridge.
You may not want to spend more money but I added a 5mm Funk Firm Achromat on top of the glass platter. This is one of the greatest upgrades I have made to my P25. The Achromat really opens up the soundstage and gives more 3 dimensionality to the records. Your VTAF problem is a blessing in disguise. Try the Achroplat you may LOVE it. If you don't it's 100% satisfaction guaranteed from musicdirect.com. I love the VTAF (and I also use a Cartridgeman isolator on my cart which means my VTAF has my arm pretty high up!!!)
I forgot to mention that I just tried the Iron Audio (Sheer Audio) acrylic platter from musicdirect and it was horrible compared to glass and Achromat. I'm sending the acrylic platter back tomorrow!!!!!
Thanks for the responses! I think Maprik has the best option for me at present. I do have the Riggle counterweight for the common (wo)man, so plenty to mess with there, but hearing that the Iron Audio (which I just pulled off the table) is bad compared to glass plus Achromat, I am very excited to actually try that blessing in disguise and will look into doing just that. I don't know what the cartridgeman isolator is, but may want to do that just so I can dial in VTA for sure!! Thanks again - this is a great forum and I appreciate your taking time to help me. Sorry I forgot in the original post to mention having the counterweight (which could affect solutions). Also, don't really know why I am so opposed to the shims, but it just doesn't sit right with me. Maprik, if you have any other interesting tidbits about the P25, please do share! Now I feel good my glass platter wasn't sold when I got the Iron Audio. So many good reviews of it (like the shelter cart), I couldn't believe it wasn't so great on my table. Alrighty - thanks!!
Hi Chapin99,

I was wondering if you got the Achromat and how it worked out for you?

Hello, Maprik! I have the VTAF and Achromats on all six of my tables. It does everything that the $500 Living Voice Mystic Mat does, but obviously much less expensive. There are also carbon fiber spacers available from Millenium Audio that fit between the cartridge and headshell. There are different sizes and they eliminate the problems mentioned in the post above.